xref: /petsc/src/mat/impls/aij/seq/aij.c (revision 3e2ddb0765c4ae0ebd7d8a17f6f110befa0ebd99)
1 /*
2     Defines the basic matrix operations for the AIJ (compressed row)
3   matrix storage format.
4 */
5 
6 #include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/
7 #include <petscblaslapack.h>
8 #include <petscbt.h>
9 #include <petsc/private/kernels/blocktranspose.h>
10 
11 PetscErrorCode MatSeqAIJSetTypeFromOptions(Mat A)
12 {
13   PetscBool flg;
14   char      type[256];
15 
16   PetscFunctionBegin;
17   PetscObjectOptionsBegin((PetscObject)A);
18   PetscCall(PetscOptionsFList("-mat_seqaij_type", "Matrix SeqAIJ type", "MatSeqAIJSetType", MatSeqAIJList, "seqaij", type, 256, &flg));
19   if (flg) PetscCall(MatSeqAIJSetType(A, type));
20   PetscOptionsEnd();
21   PetscFunctionReturn(0);
22 }
23 
24 PetscErrorCode MatGetColumnReductions_SeqAIJ(Mat A, PetscInt type, PetscReal *reductions)
25 {
26   PetscInt    i, m, n;
27   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
28 
29   PetscFunctionBegin;
30   PetscCall(MatGetSize(A, &m, &n));
31   PetscCall(PetscArrayzero(reductions, n));
32   if (type == NORM_2) {
33     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] += PetscAbsScalar(aij->a[i] * aij->a[i]);
34   } else if (type == NORM_1) {
35     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] += PetscAbsScalar(aij->a[i]);
36   } else if (type == NORM_INFINITY) {
37     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] = PetscMax(PetscAbsScalar(aij->a[i]), reductions[aij->j[i]]);
38   } else if (type == REDUCTION_SUM_REALPART || type == REDUCTION_MEAN_REALPART) {
39     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] += PetscRealPart(aij->a[i]);
40   } else if (type == REDUCTION_SUM_IMAGINARYPART || type == REDUCTION_MEAN_IMAGINARYPART) {
41     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] += PetscImaginaryPart(aij->a[i]);
42   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unknown reduction type");
43 
44   if (type == NORM_2) {
45     for (i = 0; i < n; i++) reductions[i] = PetscSqrtReal(reductions[i]);
46   } else if (type == REDUCTION_MEAN_REALPART || type == REDUCTION_MEAN_IMAGINARYPART) {
47     for (i = 0; i < n; i++) reductions[i] /= m;
48   }
49   PetscFunctionReturn(0);
50 }
51 
52 PetscErrorCode MatFindOffBlockDiagonalEntries_SeqAIJ(Mat A, IS *is)
53 {
54   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
55   PetscInt        i, m = A->rmap->n, cnt = 0, bs = A->rmap->bs;
56   const PetscInt *jj = a->j, *ii = a->i;
57   PetscInt       *rows;
58 
59   PetscFunctionBegin;
60   for (i = 0; i < m; i++) {
61     if ((ii[i] != ii[i + 1]) && ((jj[ii[i]] < bs * (i / bs)) || (jj[ii[i + 1] - 1] > bs * ((i + bs) / bs) - 1))) cnt++;
62   }
63   PetscCall(PetscMalloc1(cnt, &rows));
64   cnt = 0;
65   for (i = 0; i < m; i++) {
66     if ((ii[i] != ii[i + 1]) && ((jj[ii[i]] < bs * (i / bs)) || (jj[ii[i + 1] - 1] > bs * ((i + bs) / bs) - 1))) {
67       rows[cnt] = i;
68       cnt++;
69     }
70   }
71   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, cnt, rows, PETSC_OWN_POINTER, is));
72   PetscFunctionReturn(0);
73 }
74 
75 PetscErrorCode MatFindZeroDiagonals_SeqAIJ_Private(Mat A, PetscInt *nrows, PetscInt **zrows)
76 {
77   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
78   const MatScalar *aa;
79   PetscInt         i, m = A->rmap->n, cnt = 0;
80   const PetscInt  *ii = a->i, *jj = a->j, *diag;
81   PetscInt        *rows;
82 
83   PetscFunctionBegin;
84   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
85   PetscCall(MatMarkDiagonal_SeqAIJ(A));
86   diag = a->diag;
87   for (i = 0; i < m; i++) {
88     if ((diag[i] >= ii[i + 1]) || (jj[diag[i]] != i) || (aa[diag[i]] == 0.0)) cnt++;
89   }
90   PetscCall(PetscMalloc1(cnt, &rows));
91   cnt = 0;
92   for (i = 0; i < m; i++) {
93     if ((diag[i] >= ii[i + 1]) || (jj[diag[i]] != i) || (aa[diag[i]] == 0.0)) rows[cnt++] = i;
94   }
95   *nrows = cnt;
96   *zrows = rows;
97   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
98   PetscFunctionReturn(0);
99 }
100 
101 PetscErrorCode MatFindZeroDiagonals_SeqAIJ(Mat A, IS *zrows)
102 {
103   PetscInt nrows, *rows;
104 
105   PetscFunctionBegin;
106   *zrows = NULL;
107   PetscCall(MatFindZeroDiagonals_SeqAIJ_Private(A, &nrows, &rows));
108   PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)A), nrows, rows, PETSC_OWN_POINTER, zrows));
109   PetscFunctionReturn(0);
110 }
111 
112 PetscErrorCode MatFindNonzeroRows_SeqAIJ(Mat A, IS *keptrows)
113 {
114   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
115   const MatScalar *aa;
116   PetscInt         m = A->rmap->n, cnt = 0;
117   const PetscInt  *ii;
118   PetscInt         n, i, j, *rows;
119 
120   PetscFunctionBegin;
121   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
122   *keptrows = NULL;
123   ii        = a->i;
124   for (i = 0; i < m; i++) {
125     n = ii[i + 1] - ii[i];
126     if (!n) {
127       cnt++;
128       goto ok1;
129     }
130     for (j = ii[i]; j < ii[i + 1]; j++) {
131       if (aa[j] != 0.0) goto ok1;
132     }
133     cnt++;
134   ok1:;
135   }
136   if (!cnt) {
137     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
138     PetscFunctionReturn(0);
139   }
140   PetscCall(PetscMalloc1(A->rmap->n - cnt, &rows));
141   cnt = 0;
142   for (i = 0; i < m; i++) {
143     n = ii[i + 1] - ii[i];
144     if (!n) continue;
145     for (j = ii[i]; j < ii[i + 1]; j++) {
146       if (aa[j] != 0.0) {
147         rows[cnt++] = i;
148         break;
149       }
150     }
151   }
152   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
153   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, cnt, rows, PETSC_OWN_POINTER, keptrows));
154   PetscFunctionReturn(0);
155 }
156 
157 PetscErrorCode MatDiagonalSet_SeqAIJ(Mat Y, Vec D, InsertMode is)
158 {
159   Mat_SeqAIJ        *aij = (Mat_SeqAIJ *)Y->data;
160   PetscInt           i, m = Y->rmap->n;
161   const PetscInt    *diag;
162   MatScalar         *aa;
163   const PetscScalar *v;
164   PetscBool          missing;
165 
166   PetscFunctionBegin;
167   if (Y->assembled) {
168     PetscCall(MatMissingDiagonal_SeqAIJ(Y, &missing, NULL));
169     if (!missing) {
170       diag = aij->diag;
171       PetscCall(VecGetArrayRead(D, &v));
172       PetscCall(MatSeqAIJGetArray(Y, &aa));
173       if (is == INSERT_VALUES) {
174         for (i = 0; i < m; i++) aa[diag[i]] = v[i];
175       } else {
176         for (i = 0; i < m; i++) aa[diag[i]] += v[i];
177       }
178       PetscCall(MatSeqAIJRestoreArray(Y, &aa));
179       PetscCall(VecRestoreArrayRead(D, &v));
180       PetscFunctionReturn(0);
181     }
182     PetscCall(MatSeqAIJInvalidateDiagonal(Y));
183   }
184   PetscCall(MatDiagonalSet_Default(Y, D, is));
185   PetscFunctionReturn(0);
186 }
187 
188 PetscErrorCode MatGetRowIJ_SeqAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *m, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
189 {
190   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
191   PetscInt    i, ishift;
192 
193   PetscFunctionBegin;
194   if (m) *m = A->rmap->n;
195   if (!ia) PetscFunctionReturn(0);
196   ishift = 0;
197   if (symmetric && A->structurally_symmetric != PETSC_BOOL3_TRUE) {
198     PetscCall(MatToSymmetricIJ_SeqAIJ(A->rmap->n, a->i, a->j, PETSC_TRUE, ishift, oshift, (PetscInt **)ia, (PetscInt **)ja));
199   } else if (oshift == 1) {
200     PetscInt *tia;
201     PetscInt  nz = a->i[A->rmap->n];
202     /* malloc space and  add 1 to i and j indices */
203     PetscCall(PetscMalloc1(A->rmap->n + 1, &tia));
204     for (i = 0; i < A->rmap->n + 1; i++) tia[i] = a->i[i] + 1;
205     *ia = tia;
206     if (ja) {
207       PetscInt *tja;
208       PetscCall(PetscMalloc1(nz + 1, &tja));
209       for (i = 0; i < nz; i++) tja[i] = a->j[i] + 1;
210       *ja = tja;
211     }
212   } else {
213     *ia = a->i;
214     if (ja) *ja = a->j;
215   }
216   PetscFunctionReturn(0);
217 }
218 
219 PetscErrorCode MatRestoreRowIJ_SeqAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
220 {
221   PetscFunctionBegin;
222   if (!ia) PetscFunctionReturn(0);
223   if ((symmetric && A->structurally_symmetric != PETSC_BOOL3_TRUE) || oshift == 1) {
224     PetscCall(PetscFree(*ia));
225     if (ja) PetscCall(PetscFree(*ja));
226   }
227   PetscFunctionReturn(0);
228 }
229 
230 PetscErrorCode MatGetColumnIJ_SeqAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *nn, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
231 {
232   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
233   PetscInt    i, *collengths, *cia, *cja, n = A->cmap->n, m = A->rmap->n;
234   PetscInt    nz = a->i[m], row, *jj, mr, col;
235 
236   PetscFunctionBegin;
237   *nn = n;
238   if (!ia) PetscFunctionReturn(0);
239   if (symmetric) {
240     PetscCall(MatToSymmetricIJ_SeqAIJ(A->rmap->n, a->i, a->j, PETSC_TRUE, 0, oshift, (PetscInt **)ia, (PetscInt **)ja));
241   } else {
242     PetscCall(PetscCalloc1(n, &collengths));
243     PetscCall(PetscMalloc1(n + 1, &cia));
244     PetscCall(PetscMalloc1(nz, &cja));
245     jj = a->j;
246     for (i = 0; i < nz; i++) collengths[jj[i]]++;
247     cia[0] = oshift;
248     for (i = 0; i < n; i++) cia[i + 1] = cia[i] + collengths[i];
249     PetscCall(PetscArrayzero(collengths, n));
250     jj = a->j;
251     for (row = 0; row < m; row++) {
252       mr = a->i[row + 1] - a->i[row];
253       for (i = 0; i < mr; i++) {
254         col = *jj++;
255 
256         cja[cia[col] + collengths[col]++ - oshift] = row + oshift;
257       }
258     }
259     PetscCall(PetscFree(collengths));
260     *ia = cia;
261     *ja = cja;
262   }
263   PetscFunctionReturn(0);
264 }
265 
266 PetscErrorCode MatRestoreColumnIJ_SeqAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
267 {
268   PetscFunctionBegin;
269   if (!ia) PetscFunctionReturn(0);
270 
271   PetscCall(PetscFree(*ia));
272   PetscCall(PetscFree(*ja));
273   PetscFunctionReturn(0);
274 }
275 
276 /*
277  MatGetColumnIJ_SeqAIJ_Color() and MatRestoreColumnIJ_SeqAIJ_Color() are customized from
278  MatGetColumnIJ_SeqAIJ() and MatRestoreColumnIJ_SeqAIJ() by adding an output
279  spidx[], index of a->a, to be used in MatTransposeColoringCreate_SeqAIJ() and MatFDColoringCreate_SeqXAIJ()
280 */
281 PetscErrorCode MatGetColumnIJ_SeqAIJ_Color(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *nn, const PetscInt *ia[], const PetscInt *ja[], PetscInt *spidx[], PetscBool *done)
282 {
283   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
284   PetscInt        i, *collengths, *cia, *cja, n = A->cmap->n, m = A->rmap->n;
285   PetscInt        nz = a->i[m], row, mr, col, tmp;
286   PetscInt       *cspidx;
287   const PetscInt *jj;
288 
289   PetscFunctionBegin;
290   *nn = n;
291   if (!ia) PetscFunctionReturn(0);
292 
293   PetscCall(PetscCalloc1(n, &collengths));
294   PetscCall(PetscMalloc1(n + 1, &cia));
295   PetscCall(PetscMalloc1(nz, &cja));
296   PetscCall(PetscMalloc1(nz, &cspidx));
297   jj = a->j;
298   for (i = 0; i < nz; i++) collengths[jj[i]]++;
299   cia[0] = oshift;
300   for (i = 0; i < n; i++) cia[i + 1] = cia[i] + collengths[i];
301   PetscCall(PetscArrayzero(collengths, n));
302   jj = a->j;
303   for (row = 0; row < m; row++) {
304     mr = a->i[row + 1] - a->i[row];
305     for (i = 0; i < mr; i++) {
306       col         = *jj++;
307       tmp         = cia[col] + collengths[col]++ - oshift;
308       cspidx[tmp] = a->i[row] + i; /* index of a->j */
309       cja[tmp]    = row + oshift;
310     }
311   }
312   PetscCall(PetscFree(collengths));
313   *ia    = cia;
314   *ja    = cja;
315   *spidx = cspidx;
316   PetscFunctionReturn(0);
317 }
318 
319 PetscErrorCode MatRestoreColumnIJ_SeqAIJ_Color(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscInt *spidx[], PetscBool *done)
320 {
321   PetscFunctionBegin;
322   PetscCall(MatRestoreColumnIJ_SeqAIJ(A, oshift, symmetric, inodecompressed, n, ia, ja, done));
323   PetscCall(PetscFree(*spidx));
324   PetscFunctionReturn(0);
325 }
326 
327 PetscErrorCode MatSetValuesRow_SeqAIJ(Mat A, PetscInt row, const PetscScalar v[])
328 {
329   Mat_SeqAIJ  *a  = (Mat_SeqAIJ *)A->data;
330   PetscInt    *ai = a->i;
331   PetscScalar *aa;
332 
333   PetscFunctionBegin;
334   PetscCall(MatSeqAIJGetArray(A, &aa));
335   PetscCall(PetscArraycpy(aa + ai[row], v, ai[row + 1] - ai[row]));
336   PetscCall(MatSeqAIJRestoreArray(A, &aa));
337   PetscFunctionReturn(0);
338 }
339 
340 /*
341     MatSeqAIJSetValuesLocalFast - An optimized version of MatSetValuesLocal() for SeqAIJ matrices with several assumptions
342 
343       -   a single row of values is set with each call
344       -   no row or column indices are negative or (in error) larger than the number of rows or columns
345       -   the values are always added to the matrix, not set
346       -   no new locations are introduced in the nonzero structure of the matrix
347 
348      This does NOT assume the global column indices are sorted
349 
350 */
351 
352 #include <petsc/private/isimpl.h>
353 PetscErrorCode MatSeqAIJSetValuesLocalFast(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
354 {
355   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
356   PetscInt        low, high, t, row, nrow, i, col, l;
357   const PetscInt *rp, *ai = a->i, *ailen = a->ilen, *aj = a->j;
358   PetscInt        lastcol = -1;
359   MatScalar      *ap, value, *aa;
360   const PetscInt *ridx = A->rmap->mapping->indices, *cidx = A->cmap->mapping->indices;
361 
362   PetscFunctionBegin;
363   PetscCall(MatSeqAIJGetArray(A, &aa));
364   row  = ridx[im[0]];
365   rp   = aj + ai[row];
366   ap   = aa + ai[row];
367   nrow = ailen[row];
368   low  = 0;
369   high = nrow;
370   for (l = 0; l < n; l++) { /* loop over added columns */
371     col   = cidx[in[l]];
372     value = v[l];
373 
374     if (col <= lastcol) low = 0;
375     else high = nrow;
376     lastcol = col;
377     while (high - low > 5) {
378       t = (low + high) / 2;
379       if (rp[t] > col) high = t;
380       else low = t;
381     }
382     for (i = low; i < high; i++) {
383       if (rp[i] == col) {
384         ap[i] += value;
385         low = i + 1;
386         break;
387       }
388     }
389   }
390   PetscCall(MatSeqAIJRestoreArray(A, &aa));
391   return 0;
392 }
393 
394 PetscErrorCode MatSetValues_SeqAIJ(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
395 {
396   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
397   PetscInt   *rp, k, low, high, t, ii, row, nrow, i, col, l, rmax, N;
398   PetscInt   *imax = a->imax, *ai = a->i, *ailen = a->ilen;
399   PetscInt   *aj = a->j, nonew = a->nonew, lastcol = -1;
400   MatScalar  *ap = NULL, value = 0.0, *aa;
401   PetscBool   ignorezeroentries = a->ignorezeroentries;
402   PetscBool   roworiented       = a->roworiented;
403 
404   PetscFunctionBegin;
405   PetscCall(MatSeqAIJGetArray(A, &aa));
406   for (k = 0; k < m; k++) { /* loop over added rows */
407     row = im[k];
408     if (row < 0) continue;
409     PetscCheck(row < A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, row, A->rmap->n - 1);
410     rp = aj + ai[row];
411     if (!A->structure_only) ap = aa + ai[row];
412     rmax = imax[row];
413     nrow = ailen[row];
414     low  = 0;
415     high = nrow;
416     for (l = 0; l < n; l++) { /* loop over added columns */
417       if (in[l] < 0) continue;
418       PetscCheck(in[l] < A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column too large: col %" PetscInt_FMT " max %" PetscInt_FMT, in[l], A->cmap->n - 1);
419       col = in[l];
420       if (v && !A->structure_only) value = roworiented ? v[l + k * n] : v[k + l * m];
421       if (!A->structure_only && value == 0.0 && ignorezeroentries && is == ADD_VALUES && row != col) continue;
422 
423       if (col <= lastcol) low = 0;
424       else high = nrow;
425       lastcol = col;
426       while (high - low > 5) {
427         t = (low + high) / 2;
428         if (rp[t] > col) high = t;
429         else low = t;
430       }
431       for (i = low; i < high; i++) {
432         if (rp[i] > col) break;
433         if (rp[i] == col) {
434           if (!A->structure_only) {
435             if (is == ADD_VALUES) {
436               ap[i] += value;
437               (void)PetscLogFlops(1.0);
438             } else ap[i] = value;
439           }
440           low = i + 1;
441           goto noinsert;
442         }
443       }
444       if (value == 0.0 && ignorezeroentries && row != col) goto noinsert;
445       if (nonew == 1) goto noinsert;
446       PetscCheck(nonew != -1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new nonzero at (%" PetscInt_FMT ",%" PetscInt_FMT ") in the matrix", row, col);
447       if (A->structure_only) {
448         MatSeqXAIJReallocateAIJ_structure_only(A, A->rmap->n, 1, nrow, row, col, rmax, ai, aj, rp, imax, nonew, MatScalar);
449       } else {
450         MatSeqXAIJReallocateAIJ(A, A->rmap->n, 1, nrow, row, col, rmax, aa, ai, aj, rp, ap, imax, nonew, MatScalar);
451       }
452       N = nrow++ - 1;
453       a->nz++;
454       high++;
455       /* shift up all the later entries in this row */
456       PetscCall(PetscArraymove(rp + i + 1, rp + i, N - i + 1));
457       rp[i] = col;
458       if (!A->structure_only) {
459         PetscCall(PetscArraymove(ap + i + 1, ap + i, N - i + 1));
460         ap[i] = value;
461       }
462       low = i + 1;
463       A->nonzerostate++;
464     noinsert:;
465     }
466     ailen[row] = nrow;
467   }
468   PetscCall(MatSeqAIJRestoreArray(A, &aa));
469   PetscFunctionReturn(0);
470 }
471 
472 PetscErrorCode MatSetValues_SeqAIJ_SortedFullNoPreallocation(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
473 {
474   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
475   PetscInt   *rp, k, row;
476   PetscInt   *ai = a->i;
477   PetscInt   *aj = a->j;
478   MatScalar  *aa, *ap;
479 
480   PetscFunctionBegin;
481   PetscCheck(!A->was_assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot call on assembled matrix.");
482   PetscCheck(m * n + a->nz <= a->maxnz, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of entries in matrix will be larger than maximum nonzeros allocated for %" PetscInt_FMT " in MatSeqAIJSetTotalPreallocation()", a->maxnz);
483 
484   PetscCall(MatSeqAIJGetArray(A, &aa));
485   for (k = 0; k < m; k++) { /* loop over added rows */
486     row = im[k];
487     rp  = aj + ai[row];
488     ap  = aa + ai[row];
489 
490     PetscCall(PetscMemcpy(rp, in, n * sizeof(PetscInt)));
491     if (!A->structure_only) {
492       if (v) {
493         PetscCall(PetscMemcpy(ap, v, n * sizeof(PetscScalar)));
494         v += n;
495       } else {
496         PetscCall(PetscMemzero(ap, n * sizeof(PetscScalar)));
497       }
498     }
499     a->ilen[row]  = n;
500     a->imax[row]  = n;
501     a->i[row + 1] = a->i[row] + n;
502     a->nz += n;
503   }
504   PetscCall(MatSeqAIJRestoreArray(A, &aa));
505   PetscFunctionReturn(0);
506 }
507 
508 /*@
509     MatSeqAIJSetTotalPreallocation - Sets an upper bound on the total number of expected nonzeros in the matrix.
510 
511   Input Parameters:
512 +  A - the `MATSEQAIJ` matrix
513 -  nztotal - bound on the number of nonzeros
514 
515   Level: advanced
516 
517   Notes:
518     This can be called if you will be provided the matrix row by row (from row zero) with sorted column indices for each row.
519     Simply call `MatSetValues()` after this call to provide the matrix entries in the usual manner. This matrix may be used
520     as always with multiple matrix assemblies.
521 
522 .seealso: `MatSetOption()`, `MAT_SORTED_FULL`, `MatSetValues()`, `MatSeqAIJSetPreallocation()`
523 @*/
524 
525 PetscErrorCode MatSeqAIJSetTotalPreallocation(Mat A, PetscInt nztotal)
526 {
527   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
528 
529   PetscFunctionBegin;
530   PetscCall(PetscLayoutSetUp(A->rmap));
531   PetscCall(PetscLayoutSetUp(A->cmap));
532   a->maxnz = nztotal;
533   if (!a->imax) { PetscCall(PetscMalloc1(A->rmap->n, &a->imax)); }
534   if (!a->ilen) {
535     PetscCall(PetscMalloc1(A->rmap->n, &a->ilen));
536   } else {
537     PetscCall(PetscMemzero(a->ilen, A->rmap->n * sizeof(PetscInt)));
538   }
539 
540   /* allocate the matrix space */
541   if (A->structure_only) {
542     PetscCall(PetscMalloc1(nztotal, &a->j));
543     PetscCall(PetscMalloc1(A->rmap->n + 1, &a->i));
544   } else {
545     PetscCall(PetscMalloc3(nztotal, &a->a, nztotal, &a->j, A->rmap->n + 1, &a->i));
546   }
547   a->i[0] = 0;
548   if (A->structure_only) {
549     a->singlemalloc = PETSC_FALSE;
550     a->free_a       = PETSC_FALSE;
551   } else {
552     a->singlemalloc = PETSC_TRUE;
553     a->free_a       = PETSC_TRUE;
554   }
555   a->free_ij        = PETSC_TRUE;
556   A->ops->setvalues = MatSetValues_SeqAIJ_SortedFullNoPreallocation;
557   A->preallocated   = PETSC_TRUE;
558   PetscFunctionReturn(0);
559 }
560 
561 PetscErrorCode MatSetValues_SeqAIJ_SortedFull(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
562 {
563   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
564   PetscInt   *rp, k, row;
565   PetscInt   *ai = a->i, *ailen = a->ilen;
566   PetscInt   *aj = a->j;
567   MatScalar  *aa, *ap;
568 
569   PetscFunctionBegin;
570   PetscCall(MatSeqAIJGetArray(A, &aa));
571   for (k = 0; k < m; k++) { /* loop over added rows */
572     row = im[k];
573     PetscCheck(n <= a->imax[row], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Preallocation for row %" PetscInt_FMT " does not match number of columns provided", n);
574     rp = aj + ai[row];
575     ap = aa + ai[row];
576     if (!A->was_assembled) PetscCall(PetscMemcpy(rp, in, n * sizeof(PetscInt)));
577     if (!A->structure_only) {
578       if (v) {
579         PetscCall(PetscMemcpy(ap, v, n * sizeof(PetscScalar)));
580         v += n;
581       } else {
582         PetscCall(PetscMemzero(ap, n * sizeof(PetscScalar)));
583       }
584     }
585     ailen[row] = n;
586     a->nz += n;
587   }
588   PetscCall(MatSeqAIJRestoreArray(A, &aa));
589   PetscFunctionReturn(0);
590 }
591 
592 PetscErrorCode MatGetValues_SeqAIJ(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], PetscScalar v[])
593 {
594   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
595   PetscInt   *rp, k, low, high, t, row, nrow, i, col, l, *aj = a->j;
596   PetscInt   *ai = a->i, *ailen = a->ilen;
597   MatScalar  *ap, *aa;
598 
599   PetscFunctionBegin;
600   PetscCall(MatSeqAIJGetArray(A, &aa));
601   for (k = 0; k < m; k++) { /* loop over rows */
602     row = im[k];
603     if (row < 0) {
604       v += n;
605       continue;
606     } /* negative row */
607     PetscCheck(row < A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, row, A->rmap->n - 1);
608     rp   = aj + ai[row];
609     ap   = aa + ai[row];
610     nrow = ailen[row];
611     for (l = 0; l < n; l++) { /* loop over columns */
612       if (in[l] < 0) {
613         v++;
614         continue;
615       } /* negative column */
616       PetscCheck(in[l] < A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column too large: col %" PetscInt_FMT " max %" PetscInt_FMT, in[l], A->cmap->n - 1);
617       col  = in[l];
618       high = nrow;
619       low  = 0; /* assume unsorted */
620       while (high - low > 5) {
621         t = (low + high) / 2;
622         if (rp[t] > col) high = t;
623         else low = t;
624       }
625       for (i = low; i < high; i++) {
626         if (rp[i] > col) break;
627         if (rp[i] == col) {
628           *v++ = ap[i];
629           goto finished;
630         }
631       }
632       *v++ = 0.0;
633     finished:;
634     }
635   }
636   PetscCall(MatSeqAIJRestoreArray(A, &aa));
637   PetscFunctionReturn(0);
638 }
639 
640 PetscErrorCode MatView_SeqAIJ_Binary(Mat mat, PetscViewer viewer)
641 {
642   Mat_SeqAIJ        *A = (Mat_SeqAIJ *)mat->data;
643   const PetscScalar *av;
644   PetscInt           header[4], M, N, m, nz, i;
645   PetscInt          *rowlens;
646 
647   PetscFunctionBegin;
648   PetscCall(PetscViewerSetUp(viewer));
649 
650   M  = mat->rmap->N;
651   N  = mat->cmap->N;
652   m  = mat->rmap->n;
653   nz = A->nz;
654 
655   /* write matrix header */
656   header[0] = MAT_FILE_CLASSID;
657   header[1] = M;
658   header[2] = N;
659   header[3] = nz;
660   PetscCall(PetscViewerBinaryWrite(viewer, header, 4, PETSC_INT));
661 
662   /* fill in and store row lengths */
663   PetscCall(PetscMalloc1(m, &rowlens));
664   for (i = 0; i < m; i++) rowlens[i] = A->i[i + 1] - A->i[i];
665   PetscCall(PetscViewerBinaryWrite(viewer, rowlens, m, PETSC_INT));
666   PetscCall(PetscFree(rowlens));
667   /* store column indices */
668   PetscCall(PetscViewerBinaryWrite(viewer, A->j, nz, PETSC_INT));
669   /* store nonzero values */
670   PetscCall(MatSeqAIJGetArrayRead(mat, &av));
671   PetscCall(PetscViewerBinaryWrite(viewer, av, nz, PETSC_SCALAR));
672   PetscCall(MatSeqAIJRestoreArrayRead(mat, &av));
673 
674   /* write block size option to the viewer's .info file */
675   PetscCall(MatView_Binary_BlockSizes(mat, viewer));
676   PetscFunctionReturn(0);
677 }
678 
679 static PetscErrorCode MatView_SeqAIJ_ASCII_structonly(Mat A, PetscViewer viewer)
680 {
681   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
682   PetscInt    i, k, m = A->rmap->N;
683 
684   PetscFunctionBegin;
685   PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
686   for (i = 0; i < m; i++) {
687     PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i));
688     for (k = a->i[i]; k < a->i[i + 1]; k++) PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ") ", a->j[k]));
689     PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
690   }
691   PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
692   PetscFunctionReturn(0);
693 }
694 
695 extern PetscErrorCode MatSeqAIJFactorInfo_Matlab(Mat, PetscViewer);
696 
697 PetscErrorCode MatView_SeqAIJ_ASCII(Mat A, PetscViewer viewer)
698 {
699   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
700   const PetscScalar *av;
701   PetscInt           i, j, m = A->rmap->n;
702   const char        *name;
703   PetscViewerFormat  format;
704 
705   PetscFunctionBegin;
706   if (A->structure_only) {
707     PetscCall(MatView_SeqAIJ_ASCII_structonly(A, viewer));
708     PetscFunctionReturn(0);
709   }
710 
711   PetscCall(PetscViewerGetFormat(viewer, &format));
712   if (format == PETSC_VIEWER_ASCII_FACTOR_INFO || format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) PetscFunctionReturn(0);
713 
714   /* trigger copy to CPU if needed */
715   PetscCall(MatSeqAIJGetArrayRead(A, &av));
716   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
717   if (format == PETSC_VIEWER_ASCII_MATLAB) {
718     PetscInt nofinalvalue = 0;
719     if (m && ((a->i[m] == a->i[m - 1]) || (a->j[a->nz - 1] != A->cmap->n - 1))) {
720       /* Need a dummy value to ensure the dimension of the matrix. */
721       nofinalvalue = 1;
722     }
723     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
724     PetscCall(PetscViewerASCIIPrintf(viewer, "%% Size = %" PetscInt_FMT " %" PetscInt_FMT " \n", m, A->cmap->n));
725     PetscCall(PetscViewerASCIIPrintf(viewer, "%% Nonzeros = %" PetscInt_FMT " \n", a->nz));
726 #if defined(PETSC_USE_COMPLEX)
727     PetscCall(PetscViewerASCIIPrintf(viewer, "zzz = zeros(%" PetscInt_FMT ",4);\n", a->nz + nofinalvalue));
728 #else
729     PetscCall(PetscViewerASCIIPrintf(viewer, "zzz = zeros(%" PetscInt_FMT ",3);\n", a->nz + nofinalvalue));
730 #endif
731     PetscCall(PetscViewerASCIIPrintf(viewer, "zzz = [\n"));
732 
733     for (i = 0; i < m; i++) {
734       for (j = a->i[i]; j < a->i[i + 1]; j++) {
735 #if defined(PETSC_USE_COMPLEX)
736         PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT "  %18.16e %18.16e\n", i + 1, a->j[j] + 1, (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
737 #else
738         PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT "  %18.16e\n", i + 1, a->j[j] + 1, (double)a->a[j]));
739 #endif
740       }
741     }
742     if (nofinalvalue) {
743 #if defined(PETSC_USE_COMPLEX)
744       PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT "  %18.16e %18.16e\n", m, A->cmap->n, 0., 0.));
745 #else
746       PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT "  %18.16e\n", m, A->cmap->n, 0.0));
747 #endif
748     }
749     PetscCall(PetscObjectGetName((PetscObject)A, &name));
750     PetscCall(PetscViewerASCIIPrintf(viewer, "];\n %s = spconvert(zzz);\n", name));
751     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
752   } else if (format == PETSC_VIEWER_ASCII_COMMON) {
753     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
754     for (i = 0; i < m; i++) {
755       PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i));
756       for (j = a->i[i]; j < a->i[i + 1]; j++) {
757 #if defined(PETSC_USE_COMPLEX)
758         if (PetscImaginaryPart(a->a[j]) > 0.0 && PetscRealPart(a->a[j]) != 0.0) {
759           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
760         } else if (PetscImaginaryPart(a->a[j]) < 0.0 && PetscRealPart(a->a[j]) != 0.0) {
761           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)-PetscImaginaryPart(a->a[j])));
762         } else if (PetscRealPart(a->a[j]) != 0.0) {
763           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(a->a[j])));
764         }
765 #else
766         if (a->a[j] != 0.0) PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)a->a[j]));
767 #endif
768       }
769       PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
770     }
771     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
772   } else if (format == PETSC_VIEWER_ASCII_SYMMODU) {
773     PetscInt nzd = 0, fshift = 1, *sptr;
774     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
775     PetscCall(PetscMalloc1(m + 1, &sptr));
776     for (i = 0; i < m; i++) {
777       sptr[i] = nzd + 1;
778       for (j = a->i[i]; j < a->i[i + 1]; j++) {
779         if (a->j[j] >= i) {
780 #if defined(PETSC_USE_COMPLEX)
781           if (PetscImaginaryPart(a->a[j]) != 0.0 || PetscRealPart(a->a[j]) != 0.0) nzd++;
782 #else
783           if (a->a[j] != 0.0) nzd++;
784 #endif
785         }
786       }
787     }
788     sptr[m] = nzd + 1;
789     PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT "\n\n", m, nzd));
790     for (i = 0; i < m + 1; i += 6) {
791       if (i + 4 < m) {
792         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1], sptr[i + 2], sptr[i + 3], sptr[i + 4], sptr[i + 5]));
793       } else if (i + 3 < m) {
794         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1], sptr[i + 2], sptr[i + 3], sptr[i + 4]));
795       } else if (i + 2 < m) {
796         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1], sptr[i + 2], sptr[i + 3]));
797       } else if (i + 1 < m) {
798         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1], sptr[i + 2]));
799       } else if (i < m) {
800         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1]));
801       } else {
802         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT "\n", sptr[i]));
803       }
804     }
805     PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
806     PetscCall(PetscFree(sptr));
807     for (i = 0; i < m; i++) {
808       for (j = a->i[i]; j < a->i[i + 1]; j++) {
809         if (a->j[j] >= i) PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " ", a->j[j] + fshift));
810       }
811       PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
812     }
813     PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
814     for (i = 0; i < m; i++) {
815       for (j = a->i[i]; j < a->i[i + 1]; j++) {
816         if (a->j[j] >= i) {
817 #if defined(PETSC_USE_COMPLEX)
818           if (PetscImaginaryPart(a->a[j]) != 0.0 || PetscRealPart(a->a[j]) != 0.0) PetscCall(PetscViewerASCIIPrintf(viewer, " %18.16e %18.16e ", (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
819 #else
820           if (a->a[j] != 0.0) PetscCall(PetscViewerASCIIPrintf(viewer, " %18.16e ", (double)a->a[j]));
821 #endif
822         }
823       }
824       PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
825     }
826     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
827   } else if (format == PETSC_VIEWER_ASCII_DENSE) {
828     PetscInt    cnt = 0, jcnt;
829     PetscScalar value;
830 #if defined(PETSC_USE_COMPLEX)
831     PetscBool realonly = PETSC_TRUE;
832 
833     for (i = 0; i < a->i[m]; i++) {
834       if (PetscImaginaryPart(a->a[i]) != 0.0) {
835         realonly = PETSC_FALSE;
836         break;
837       }
838     }
839 #endif
840 
841     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
842     for (i = 0; i < m; i++) {
843       jcnt = 0;
844       for (j = 0; j < A->cmap->n; j++) {
845         if (jcnt < a->i[i + 1] - a->i[i] && j == a->j[cnt]) {
846           value = a->a[cnt++];
847           jcnt++;
848         } else {
849           value = 0.0;
850         }
851 #if defined(PETSC_USE_COMPLEX)
852         if (realonly) {
853           PetscCall(PetscViewerASCIIPrintf(viewer, " %7.5e ", (double)PetscRealPart(value)));
854         } else {
855           PetscCall(PetscViewerASCIIPrintf(viewer, " %7.5e+%7.5e i ", (double)PetscRealPart(value), (double)PetscImaginaryPart(value)));
856         }
857 #else
858         PetscCall(PetscViewerASCIIPrintf(viewer, " %7.5e ", (double)value));
859 #endif
860       }
861       PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
862     }
863     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
864   } else if (format == PETSC_VIEWER_ASCII_MATRIXMARKET) {
865     PetscInt fshift = 1;
866     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
867 #if defined(PETSC_USE_COMPLEX)
868     PetscCall(PetscViewerASCIIPrintf(viewer, "%%%%MatrixMarket matrix coordinate complex general\n"));
869 #else
870     PetscCall(PetscViewerASCIIPrintf(viewer, "%%%%MatrixMarket matrix coordinate real general\n"));
871 #endif
872     PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", m, A->cmap->n, a->nz));
873     for (i = 0; i < m; i++) {
874       for (j = a->i[i]; j < a->i[i + 1]; j++) {
875 #if defined(PETSC_USE_COMPLEX)
876         PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT " %g %g\n", i + fshift, a->j[j] + fshift, (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
877 #else
878         PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT " %g\n", i + fshift, a->j[j] + fshift, (double)a->a[j]));
879 #endif
880       }
881     }
882     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
883   } else {
884     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
885     if (A->factortype) {
886       for (i = 0; i < m; i++) {
887         PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i));
888         /* L part */
889         for (j = a->i[i]; j < a->i[i + 1]; j++) {
890 #if defined(PETSC_USE_COMPLEX)
891           if (PetscImaginaryPart(a->a[j]) > 0.0) {
892             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
893           } else if (PetscImaginaryPart(a->a[j]) < 0.0) {
894             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)(-PetscImaginaryPart(a->a[j]))));
895           } else {
896             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(a->a[j])));
897           }
898 #else
899           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)a->a[j]));
900 #endif
901         }
902         /* diagonal */
903         j = a->diag[i];
904 #if defined(PETSC_USE_COMPLEX)
905         if (PetscImaginaryPart(a->a[j]) > 0.0) {
906           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(1.0 / a->a[j]), (double)PetscImaginaryPart(1.0 / a->a[j])));
907         } else if (PetscImaginaryPart(a->a[j]) < 0.0) {
908           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(1.0 / a->a[j]), (double)(-PetscImaginaryPart(1.0 / a->a[j]))));
909         } else {
910           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(1.0 / a->a[j])));
911         }
912 #else
913         PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)(1.0 / a->a[j])));
914 #endif
915 
916         /* U part */
917         for (j = a->diag[i + 1] + 1; j < a->diag[i]; j++) {
918 #if defined(PETSC_USE_COMPLEX)
919           if (PetscImaginaryPart(a->a[j]) > 0.0) {
920             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
921           } else if (PetscImaginaryPart(a->a[j]) < 0.0) {
922             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)(-PetscImaginaryPart(a->a[j]))));
923           } else {
924             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(a->a[j])));
925           }
926 #else
927           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)a->a[j]));
928 #endif
929         }
930         PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
931       }
932     } else {
933       for (i = 0; i < m; i++) {
934         PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i));
935         for (j = a->i[i]; j < a->i[i + 1]; j++) {
936 #if defined(PETSC_USE_COMPLEX)
937           if (PetscImaginaryPart(a->a[j]) > 0.0) {
938             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
939           } else if (PetscImaginaryPart(a->a[j]) < 0.0) {
940             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)-PetscImaginaryPart(a->a[j])));
941           } else {
942             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(a->a[j])));
943           }
944 #else
945           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)a->a[j]));
946 #endif
947         }
948         PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
949       }
950     }
951     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
952   }
953   PetscCall(PetscViewerFlush(viewer));
954   PetscFunctionReturn(0);
955 }
956 
957 #include <petscdraw.h>
958 PetscErrorCode MatView_SeqAIJ_Draw_Zoom(PetscDraw draw, void *Aa)
959 {
960   Mat                A = (Mat)Aa;
961   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
962   PetscInt           i, j, m = A->rmap->n;
963   int                color;
964   PetscReal          xl, yl, xr, yr, x_l, x_r, y_l, y_r;
965   PetscViewer        viewer;
966   PetscViewerFormat  format;
967   const PetscScalar *aa;
968 
969   PetscFunctionBegin;
970   PetscCall(PetscObjectQuery((PetscObject)A, "Zoomviewer", (PetscObject *)&viewer));
971   PetscCall(PetscViewerGetFormat(viewer, &format));
972   PetscCall(PetscDrawGetCoordinates(draw, &xl, &yl, &xr, &yr));
973 
974   /* loop over matrix elements drawing boxes */
975   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
976   if (format != PETSC_VIEWER_DRAW_CONTOUR) {
977     PetscDrawCollectiveBegin(draw);
978     /* Blue for negative, Cyan for zero and  Red for positive */
979     color = PETSC_DRAW_BLUE;
980     for (i = 0; i < m; i++) {
981       y_l = m - i - 1.0;
982       y_r = y_l + 1.0;
983       for (j = a->i[i]; j < a->i[i + 1]; j++) {
984         x_l = a->j[j];
985         x_r = x_l + 1.0;
986         if (PetscRealPart(aa[j]) >= 0.) continue;
987         PetscCall(PetscDrawRectangle(draw, x_l, y_l, x_r, y_r, color, color, color, color));
988       }
989     }
990     color = PETSC_DRAW_CYAN;
991     for (i = 0; i < m; i++) {
992       y_l = m - i - 1.0;
993       y_r = y_l + 1.0;
994       for (j = a->i[i]; j < a->i[i + 1]; j++) {
995         x_l = a->j[j];
996         x_r = x_l + 1.0;
997         if (aa[j] != 0.) continue;
998         PetscCall(PetscDrawRectangle(draw, x_l, y_l, x_r, y_r, color, color, color, color));
999       }
1000     }
1001     color = PETSC_DRAW_RED;
1002     for (i = 0; i < m; i++) {
1003       y_l = m - i - 1.0;
1004       y_r = y_l + 1.0;
1005       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1006         x_l = a->j[j];
1007         x_r = x_l + 1.0;
1008         if (PetscRealPart(aa[j]) <= 0.) continue;
1009         PetscCall(PetscDrawRectangle(draw, x_l, y_l, x_r, y_r, color, color, color, color));
1010       }
1011     }
1012     PetscDrawCollectiveEnd(draw);
1013   } else {
1014     /* use contour shading to indicate magnitude of values */
1015     /* first determine max of all nonzero values */
1016     PetscReal minv = 0.0, maxv = 0.0;
1017     PetscInt  nz = a->nz, count = 0;
1018     PetscDraw popup;
1019 
1020     for (i = 0; i < nz; i++) {
1021       if (PetscAbsScalar(aa[i]) > maxv) maxv = PetscAbsScalar(aa[i]);
1022     }
1023     if (minv >= maxv) maxv = minv + PETSC_SMALL;
1024     PetscCall(PetscDrawGetPopup(draw, &popup));
1025     PetscCall(PetscDrawScalePopup(popup, minv, maxv));
1026 
1027     PetscDrawCollectiveBegin(draw);
1028     for (i = 0; i < m; i++) {
1029       y_l = m - i - 1.0;
1030       y_r = y_l + 1.0;
1031       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1032         x_l   = a->j[j];
1033         x_r   = x_l + 1.0;
1034         color = PetscDrawRealToColor(PetscAbsScalar(aa[count]), minv, maxv);
1035         PetscCall(PetscDrawRectangle(draw, x_l, y_l, x_r, y_r, color, color, color, color));
1036         count++;
1037       }
1038     }
1039     PetscDrawCollectiveEnd(draw);
1040   }
1041   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1042   PetscFunctionReturn(0);
1043 }
1044 
1045 #include <petscdraw.h>
1046 PetscErrorCode MatView_SeqAIJ_Draw(Mat A, PetscViewer viewer)
1047 {
1048   PetscDraw draw;
1049   PetscReal xr, yr, xl, yl, h, w;
1050   PetscBool isnull;
1051 
1052   PetscFunctionBegin;
1053   PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
1054   PetscCall(PetscDrawIsNull(draw, &isnull));
1055   if (isnull) PetscFunctionReturn(0);
1056 
1057   xr = A->cmap->n;
1058   yr = A->rmap->n;
1059   h  = yr / 10.0;
1060   w  = xr / 10.0;
1061   xr += w;
1062   yr += h;
1063   xl = -w;
1064   yl = -h;
1065   PetscCall(PetscDrawSetCoordinates(draw, xl, yl, xr, yr));
1066   PetscCall(PetscObjectCompose((PetscObject)A, "Zoomviewer", (PetscObject)viewer));
1067   PetscCall(PetscDrawZoom(draw, MatView_SeqAIJ_Draw_Zoom, A));
1068   PetscCall(PetscObjectCompose((PetscObject)A, "Zoomviewer", NULL));
1069   PetscCall(PetscDrawSave(draw));
1070   PetscFunctionReturn(0);
1071 }
1072 
1073 PetscErrorCode MatView_SeqAIJ(Mat A, PetscViewer viewer)
1074 {
1075   PetscBool iascii, isbinary, isdraw;
1076 
1077   PetscFunctionBegin;
1078   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
1079   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
1080   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
1081   if (iascii) PetscCall(MatView_SeqAIJ_ASCII(A, viewer));
1082   else if (isbinary) PetscCall(MatView_SeqAIJ_Binary(A, viewer));
1083   else if (isdraw) PetscCall(MatView_SeqAIJ_Draw(A, viewer));
1084   PetscCall(MatView_SeqAIJ_Inode(A, viewer));
1085   PetscFunctionReturn(0);
1086 }
1087 
1088 PetscErrorCode MatAssemblyEnd_SeqAIJ(Mat A, MatAssemblyType mode)
1089 {
1090   Mat_SeqAIJ *a      = (Mat_SeqAIJ *)A->data;
1091   PetscInt    fshift = 0, i, *ai = a->i, *aj = a->j, *imax = a->imax;
1092   PetscInt    m = A->rmap->n, *ip, N, *ailen = a->ilen, rmax = 0;
1093   MatScalar  *aa    = a->a, *ap;
1094   PetscReal   ratio = 0.6;
1095 
1096   PetscFunctionBegin;
1097   if (mode == MAT_FLUSH_ASSEMBLY) PetscFunctionReturn(0);
1098   PetscCall(MatSeqAIJInvalidateDiagonal(A));
1099   if (A->was_assembled && A->ass_nonzerostate == A->nonzerostate) {
1100     /* we need to respect users asking to use or not the inodes routine in between matrix assemblies */
1101     PetscCall(MatAssemblyEnd_SeqAIJ_Inode(A, mode));
1102     PetscFunctionReturn(0);
1103   }
1104 
1105   if (m) rmax = ailen[0]; /* determine row with most nonzeros */
1106   for (i = 1; i < m; i++) {
1107     /* move each row back by the amount of empty slots (fshift) before it*/
1108     fshift += imax[i - 1] - ailen[i - 1];
1109     rmax = PetscMax(rmax, ailen[i]);
1110     if (fshift) {
1111       ip = aj + ai[i];
1112       ap = aa + ai[i];
1113       N  = ailen[i];
1114       PetscCall(PetscArraymove(ip - fshift, ip, N));
1115       if (!A->structure_only) PetscCall(PetscArraymove(ap - fshift, ap, N));
1116     }
1117     ai[i] = ai[i - 1] + ailen[i - 1];
1118   }
1119   if (m) {
1120     fshift += imax[m - 1] - ailen[m - 1];
1121     ai[m] = ai[m - 1] + ailen[m - 1];
1122   }
1123 
1124   /* reset ilen and imax for each row */
1125   a->nonzerorowcnt = 0;
1126   if (A->structure_only) {
1127     PetscCall(PetscFree(a->imax));
1128     PetscCall(PetscFree(a->ilen));
1129   } else { /* !A->structure_only */
1130     for (i = 0; i < m; i++) {
1131       ailen[i] = imax[i] = ai[i + 1] - ai[i];
1132       a->nonzerorowcnt += ((ai[i + 1] - ai[i]) > 0);
1133     }
1134   }
1135   a->nz = ai[m];
1136   PetscCheck(!fshift || a->nounused != -1, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Unused space detected in matrix: %" PetscInt_FMT " X %" PetscInt_FMT ", %" PetscInt_FMT " unneeded", m, A->cmap->n, fshift);
1137 
1138   PetscCall(MatMarkDiagonal_SeqAIJ(A));
1139   PetscCall(PetscInfo(A, "Matrix size: %" PetscInt_FMT " X %" PetscInt_FMT "; storage space: %" PetscInt_FMT " unneeded,%" PetscInt_FMT " used\n", m, A->cmap->n, fshift, a->nz));
1140   PetscCall(PetscInfo(A, "Number of mallocs during MatSetValues() is %" PetscInt_FMT "\n", a->reallocs));
1141   PetscCall(PetscInfo(A, "Maximum nonzeros in any row is %" PetscInt_FMT "\n", rmax));
1142 
1143   A->info.mallocs += a->reallocs;
1144   a->reallocs         = 0;
1145   A->info.nz_unneeded = (PetscReal)fshift;
1146   a->rmax             = rmax;
1147 
1148   if (!A->structure_only) PetscCall(MatCheckCompressedRow(A, a->nonzerorowcnt, &a->compressedrow, a->i, m, ratio));
1149   PetscCall(MatAssemblyEnd_SeqAIJ_Inode(A, mode));
1150   PetscFunctionReturn(0);
1151 }
1152 
1153 PetscErrorCode MatRealPart_SeqAIJ(Mat A)
1154 {
1155   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1156   PetscInt    i, nz = a->nz;
1157   MatScalar  *aa;
1158 
1159   PetscFunctionBegin;
1160   PetscCall(MatSeqAIJGetArray(A, &aa));
1161   for (i = 0; i < nz; i++) aa[i] = PetscRealPart(aa[i]);
1162   PetscCall(MatSeqAIJRestoreArray(A, &aa));
1163   PetscCall(MatSeqAIJInvalidateDiagonal(A));
1164   PetscFunctionReturn(0);
1165 }
1166 
1167 PetscErrorCode MatImaginaryPart_SeqAIJ(Mat A)
1168 {
1169   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1170   PetscInt    i, nz = a->nz;
1171   MatScalar  *aa;
1172 
1173   PetscFunctionBegin;
1174   PetscCall(MatSeqAIJGetArray(A, &aa));
1175   for (i = 0; i < nz; i++) aa[i] = PetscImaginaryPart(aa[i]);
1176   PetscCall(MatSeqAIJRestoreArray(A, &aa));
1177   PetscCall(MatSeqAIJInvalidateDiagonal(A));
1178   PetscFunctionReturn(0);
1179 }
1180 
1181 PetscErrorCode MatZeroEntries_SeqAIJ(Mat A)
1182 {
1183   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1184   MatScalar  *aa;
1185 
1186   PetscFunctionBegin;
1187   PetscCall(MatSeqAIJGetArrayWrite(A, &aa));
1188   PetscCall(PetscArrayzero(aa, a->i[A->rmap->n]));
1189   PetscCall(MatSeqAIJRestoreArrayWrite(A, &aa));
1190   PetscCall(MatSeqAIJInvalidateDiagonal(A));
1191   PetscFunctionReturn(0);
1192 }
1193 
1194 PETSC_INTERN PetscErrorCode MatResetPreallocationCOO_SeqAIJ(Mat A)
1195 {
1196   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1197 
1198   PetscFunctionBegin;
1199   PetscCall(PetscFree(a->perm));
1200   PetscCall(PetscFree(a->jmap));
1201   PetscFunctionReturn(0);
1202 }
1203 
1204 PetscErrorCode MatDestroy_SeqAIJ(Mat A)
1205 {
1206   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1207 
1208   PetscFunctionBegin;
1209 #if defined(PETSC_USE_LOG)
1210   PetscLogObjectState((PetscObject)A, "Rows=%" PetscInt_FMT ", Cols=%" PetscInt_FMT ", NZ=%" PetscInt_FMT, A->rmap->n, A->cmap->n, a->nz);
1211 #endif
1212   PetscCall(MatSeqXAIJFreeAIJ(A, &a->a, &a->j, &a->i));
1213   PetscCall(MatResetPreallocationCOO_SeqAIJ(A));
1214   PetscCall(ISDestroy(&a->row));
1215   PetscCall(ISDestroy(&a->col));
1216   PetscCall(PetscFree(a->diag));
1217   PetscCall(PetscFree(a->ibdiag));
1218   PetscCall(PetscFree(a->imax));
1219   PetscCall(PetscFree(a->ilen));
1220   PetscCall(PetscFree(a->ipre));
1221   PetscCall(PetscFree3(a->idiag, a->mdiag, a->ssor_work));
1222   PetscCall(PetscFree(a->solve_work));
1223   PetscCall(ISDestroy(&a->icol));
1224   PetscCall(PetscFree(a->saved_values));
1225   PetscCall(PetscFree2(a->compressedrow.i, a->compressedrow.rindex));
1226   PetscCall(MatDestroy_SeqAIJ_Inode(A));
1227   PetscCall(PetscFree(A->data));
1228 
1229   /* MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted may allocate this.
1230      That function is so heavily used (sometimes in an hidden way through multnumeric function pointers)
1231      that is hard to properly add this data to the MatProduct data. We free it here to avoid
1232      users reusing the matrix object with different data to incur in obscure segmentation faults
1233      due to different matrix sizes */
1234   PetscCall(PetscObjectCompose((PetscObject)A, "__PETSc__ab_dense", NULL));
1235 
1236   PetscCall(PetscObjectChangeTypeName((PetscObject)A, NULL));
1237   PetscCall(PetscObjectComposeFunction((PetscObject)A, "PetscMatlabEnginePut_C", NULL));
1238   PetscCall(PetscObjectComposeFunction((PetscObject)A, "PetscMatlabEngineGet_C", NULL));
1239   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqAIJSetColumnIndices_C", NULL));
1240   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatStoreValues_C", NULL));
1241   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatRetrieveValues_C", NULL));
1242   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqsbaij_C", NULL));
1243   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqbaij_C", NULL));
1244   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijperm_C", NULL));
1245   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijsell_C", NULL));
1246 #if defined(PETSC_HAVE_MKL_SPARSE)
1247   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijmkl_C", NULL));
1248 #endif
1249 #if defined(PETSC_HAVE_CUDA)
1250   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijcusparse_C", NULL));
1251   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaijcusparse_seqaij_C", NULL));
1252   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaij_seqaijcusparse_C", NULL));
1253 #endif
1254 #if defined(PETSC_HAVE_KOKKOS_KERNELS)
1255   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijkokkos_C", NULL));
1256 #endif
1257   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijcrl_C", NULL));
1258 #if defined(PETSC_HAVE_ELEMENTAL)
1259   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_elemental_C", NULL));
1260 #endif
1261 #if defined(PETSC_HAVE_SCALAPACK)
1262   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_scalapack_C", NULL));
1263 #endif
1264 #if defined(PETSC_HAVE_HYPRE)
1265   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_hypre_C", NULL));
1266   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_transpose_seqaij_seqaij_C", NULL));
1267 #endif
1268   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqdense_C", NULL));
1269   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqsell_C", NULL));
1270   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_is_C", NULL));
1271   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatIsTranspose_C", NULL));
1272   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatIsHermitianTranspose_C", NULL));
1273   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqAIJSetPreallocation_C", NULL));
1274   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatResetPreallocation_C", NULL));
1275   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqAIJSetPreallocationCSR_C", NULL));
1276   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatReorderForNonzeroDiagonal_C", NULL));
1277   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_is_seqaij_C", NULL));
1278   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqdense_seqaij_C", NULL));
1279   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaij_seqaij_C", NULL));
1280   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqAIJKron_C", NULL));
1281   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSetPreallocationCOO_C", NULL));
1282   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSetValuesCOO_C", NULL));
1283   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatFactorGetSolverType_C", NULL));
1284   /* these calls do not belong here: the subclasses Duplicate/Destroy are wrong */
1285   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaijsell_seqaij_C", NULL));
1286   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaijperm_seqaij_C", NULL));
1287   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijviennacl_C", NULL));
1288   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaijviennacl_seqdense_C", NULL));
1289   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaijviennacl_seqaij_C", NULL));
1290   PetscFunctionReturn(0);
1291 }
1292 
1293 PetscErrorCode MatSetOption_SeqAIJ(Mat A, MatOption op, PetscBool flg)
1294 {
1295   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1296 
1297   PetscFunctionBegin;
1298   switch (op) {
1299   case MAT_ROW_ORIENTED:
1300     a->roworiented = flg;
1301     break;
1302   case MAT_KEEP_NONZERO_PATTERN:
1303     a->keepnonzeropattern = flg;
1304     break;
1305   case MAT_NEW_NONZERO_LOCATIONS:
1306     a->nonew = (flg ? 0 : 1);
1307     break;
1308   case MAT_NEW_NONZERO_LOCATION_ERR:
1309     a->nonew = (flg ? -1 : 0);
1310     break;
1311   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1312     a->nonew = (flg ? -2 : 0);
1313     break;
1314   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1315     a->nounused = (flg ? -1 : 0);
1316     break;
1317   case MAT_IGNORE_ZERO_ENTRIES:
1318     a->ignorezeroentries = flg;
1319     break;
1320   case MAT_SPD:
1321   case MAT_SYMMETRIC:
1322   case MAT_STRUCTURALLY_SYMMETRIC:
1323   case MAT_HERMITIAN:
1324   case MAT_SYMMETRY_ETERNAL:
1325   case MAT_STRUCTURE_ONLY:
1326   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
1327   case MAT_SPD_ETERNAL:
1328     /* if the diagonal matrix is square it inherits some of the properties above */
1329     break;
1330   case MAT_FORCE_DIAGONAL_ENTRIES:
1331   case MAT_IGNORE_OFF_PROC_ENTRIES:
1332   case MAT_USE_HASH_TABLE:
1333     PetscCall(PetscInfo(A, "Option %s ignored\n", MatOptions[op]));
1334     break;
1335   case MAT_USE_INODES:
1336     PetscCall(MatSetOption_SeqAIJ_Inode(A, MAT_USE_INODES, flg));
1337     break;
1338   case MAT_SUBMAT_SINGLEIS:
1339     A->submat_singleis = flg;
1340     break;
1341   case MAT_SORTED_FULL:
1342     if (flg) A->ops->setvalues = MatSetValues_SeqAIJ_SortedFull;
1343     else A->ops->setvalues = MatSetValues_SeqAIJ;
1344     break;
1345   case MAT_FORM_EXPLICIT_TRANSPOSE:
1346     A->form_explicit_transpose = flg;
1347     break;
1348   default:
1349     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "unknown option %d", op);
1350   }
1351   PetscFunctionReturn(0);
1352 }
1353 
1354 PetscErrorCode MatGetDiagonal_SeqAIJ(Mat A, Vec v)
1355 {
1356   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1357   PetscInt           i, j, n, *ai = a->i, *aj = a->j;
1358   PetscScalar       *x;
1359   const PetscScalar *aa;
1360 
1361   PetscFunctionBegin;
1362   PetscCall(VecGetLocalSize(v, &n));
1363   PetscCheck(n == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
1364   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
1365   if (A->factortype == MAT_FACTOR_ILU || A->factortype == MAT_FACTOR_LU) {
1366     PetscInt *diag = a->diag;
1367     PetscCall(VecGetArrayWrite(v, &x));
1368     for (i = 0; i < n; i++) x[i] = 1.0 / aa[diag[i]];
1369     PetscCall(VecRestoreArrayWrite(v, &x));
1370     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1371     PetscFunctionReturn(0);
1372   }
1373 
1374   PetscCall(VecGetArrayWrite(v, &x));
1375   for (i = 0; i < n; i++) {
1376     x[i] = 0.0;
1377     for (j = ai[i]; j < ai[i + 1]; j++) {
1378       if (aj[j] == i) {
1379         x[i] = aa[j];
1380         break;
1381       }
1382     }
1383   }
1384   PetscCall(VecRestoreArrayWrite(v, &x));
1385   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1386   PetscFunctionReturn(0);
1387 }
1388 
1389 #include <../src/mat/impls/aij/seq/ftn-kernels/fmult.h>
1390 PetscErrorCode MatMultTransposeAdd_SeqAIJ(Mat A, Vec xx, Vec zz, Vec yy)
1391 {
1392   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1393   const MatScalar   *aa;
1394   PetscScalar       *y;
1395   const PetscScalar *x;
1396   PetscInt           m = A->rmap->n;
1397 #if !defined(PETSC_USE_FORTRAN_KERNEL_MULTTRANSPOSEAIJ)
1398   const MatScalar  *v;
1399   PetscScalar       alpha;
1400   PetscInt          n, i, j;
1401   const PetscInt   *idx, *ii, *ridx = NULL;
1402   Mat_CompressedRow cprow    = a->compressedrow;
1403   PetscBool         usecprow = cprow.use;
1404 #endif
1405 
1406   PetscFunctionBegin;
1407   if (zz != yy) PetscCall(VecCopy(zz, yy));
1408   PetscCall(VecGetArrayRead(xx, &x));
1409   PetscCall(VecGetArray(yy, &y));
1410   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
1411 
1412 #if defined(PETSC_USE_FORTRAN_KERNEL_MULTTRANSPOSEAIJ)
1413   fortranmulttransposeaddaij_(&m, x, a->i, a->j, aa, y);
1414 #else
1415   if (usecprow) {
1416     m = cprow.nrows;
1417     ii = cprow.i;
1418     ridx = cprow.rindex;
1419   } else {
1420     ii = a->i;
1421   }
1422   for (i = 0; i < m; i++) {
1423     idx = a->j + ii[i];
1424     v = aa + ii[i];
1425     n = ii[i + 1] - ii[i];
1426     if (usecprow) {
1427       alpha = x[ridx[i]];
1428     } else {
1429       alpha = x[i];
1430     }
1431     for (j = 0; j < n; j++) y[idx[j]] += alpha * v[j];
1432   }
1433 #endif
1434   PetscCall(PetscLogFlops(2.0 * a->nz));
1435   PetscCall(VecRestoreArrayRead(xx, &x));
1436   PetscCall(VecRestoreArray(yy, &y));
1437   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1438   PetscFunctionReturn(0);
1439 }
1440 
1441 PetscErrorCode MatMultTranspose_SeqAIJ(Mat A, Vec xx, Vec yy)
1442 {
1443   PetscFunctionBegin;
1444   PetscCall(VecSet(yy, 0.0));
1445   PetscCall(MatMultTransposeAdd_SeqAIJ(A, xx, yy, yy));
1446   PetscFunctionReturn(0);
1447 }
1448 
1449 #include <../src/mat/impls/aij/seq/ftn-kernels/fmult.h>
1450 
1451 PetscErrorCode MatMult_SeqAIJ(Mat A, Vec xx, Vec yy)
1452 {
1453   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1454   PetscScalar       *y;
1455   const PetscScalar *x;
1456   const MatScalar   *aa, *a_a;
1457   PetscInt           m = A->rmap->n;
1458   const PetscInt    *aj, *ii, *ridx = NULL;
1459   PetscInt           n, i;
1460   PetscScalar        sum;
1461   PetscBool          usecprow = a->compressedrow.use;
1462 
1463 #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
1464   #pragma disjoint(*x, *y, *aa)
1465 #endif
1466 
1467   PetscFunctionBegin;
1468   if (a->inode.use && a->inode.checked) {
1469     PetscCall(MatMult_SeqAIJ_Inode(A, xx, yy));
1470     PetscFunctionReturn(0);
1471   }
1472   PetscCall(MatSeqAIJGetArrayRead(A, &a_a));
1473   PetscCall(VecGetArrayRead(xx, &x));
1474   PetscCall(VecGetArray(yy, &y));
1475   ii = a->i;
1476   if (usecprow) { /* use compressed row format */
1477     PetscCall(PetscArrayzero(y, m));
1478     m    = a->compressedrow.nrows;
1479     ii   = a->compressedrow.i;
1480     ridx = a->compressedrow.rindex;
1481     for (i = 0; i < m; i++) {
1482       n   = ii[i + 1] - ii[i];
1483       aj  = a->j + ii[i];
1484       aa  = a_a + ii[i];
1485       sum = 0.0;
1486       PetscSparseDensePlusDot(sum, x, aa, aj, n);
1487       /* for (j=0; j<n; j++) sum += (*aa++)*x[*aj++]; */
1488       y[*ridx++] = sum;
1489     }
1490   } else { /* do not use compressed row format */
1491 #if defined(PETSC_USE_FORTRAN_KERNEL_MULTAIJ)
1492     aj = a->j;
1493     aa = a_a;
1494     fortranmultaij_(&m, x, ii, aj, aa, y);
1495 #else
1496     for (i = 0; i < m; i++) {
1497       n = ii[i + 1] - ii[i];
1498       aj = a->j + ii[i];
1499       aa = a_a + ii[i];
1500       sum = 0.0;
1501       PetscSparseDensePlusDot(sum, x, aa, aj, n);
1502       y[i] = sum;
1503     }
1504 #endif
1505   }
1506   PetscCall(PetscLogFlops(2.0 * a->nz - a->nonzerorowcnt));
1507   PetscCall(VecRestoreArrayRead(xx, &x));
1508   PetscCall(VecRestoreArray(yy, &y));
1509   PetscCall(MatSeqAIJRestoreArrayRead(A, &a_a));
1510   PetscFunctionReturn(0);
1511 }
1512 
1513 PetscErrorCode MatMultMax_SeqAIJ(Mat A, Vec xx, Vec yy)
1514 {
1515   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1516   PetscScalar       *y;
1517   const PetscScalar *x;
1518   const MatScalar   *aa, *a_a;
1519   PetscInt           m = A->rmap->n;
1520   const PetscInt    *aj, *ii, *ridx   = NULL;
1521   PetscInt           n, i, nonzerorow = 0;
1522   PetscScalar        sum;
1523   PetscBool          usecprow = a->compressedrow.use;
1524 
1525 #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
1526   #pragma disjoint(*x, *y, *aa)
1527 #endif
1528 
1529   PetscFunctionBegin;
1530   PetscCall(MatSeqAIJGetArrayRead(A, &a_a));
1531   PetscCall(VecGetArrayRead(xx, &x));
1532   PetscCall(VecGetArray(yy, &y));
1533   if (usecprow) { /* use compressed row format */
1534     m    = a->compressedrow.nrows;
1535     ii   = a->compressedrow.i;
1536     ridx = a->compressedrow.rindex;
1537     for (i = 0; i < m; i++) {
1538       n   = ii[i + 1] - ii[i];
1539       aj  = a->j + ii[i];
1540       aa  = a_a + ii[i];
1541       sum = 0.0;
1542       nonzerorow += (n > 0);
1543       PetscSparseDenseMaxDot(sum, x, aa, aj, n);
1544       /* for (j=0; j<n; j++) sum += (*aa++)*x[*aj++]; */
1545       y[*ridx++] = sum;
1546     }
1547   } else { /* do not use compressed row format */
1548     ii = a->i;
1549     for (i = 0; i < m; i++) {
1550       n   = ii[i + 1] - ii[i];
1551       aj  = a->j + ii[i];
1552       aa  = a_a + ii[i];
1553       sum = 0.0;
1554       nonzerorow += (n > 0);
1555       PetscSparseDenseMaxDot(sum, x, aa, aj, n);
1556       y[i] = sum;
1557     }
1558   }
1559   PetscCall(PetscLogFlops(2.0 * a->nz - nonzerorow));
1560   PetscCall(VecRestoreArrayRead(xx, &x));
1561   PetscCall(VecRestoreArray(yy, &y));
1562   PetscCall(MatSeqAIJRestoreArrayRead(A, &a_a));
1563   PetscFunctionReturn(0);
1564 }
1565 
1566 PetscErrorCode MatMultAddMax_SeqAIJ(Mat A, Vec xx, Vec yy, Vec zz)
1567 {
1568   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1569   PetscScalar       *y, *z;
1570   const PetscScalar *x;
1571   const MatScalar   *aa, *a_a;
1572   PetscInt           m = A->rmap->n, *aj, *ii;
1573   PetscInt           n, i, *ridx = NULL;
1574   PetscScalar        sum;
1575   PetscBool          usecprow = a->compressedrow.use;
1576 
1577   PetscFunctionBegin;
1578   PetscCall(MatSeqAIJGetArrayRead(A, &a_a));
1579   PetscCall(VecGetArrayRead(xx, &x));
1580   PetscCall(VecGetArrayPair(yy, zz, &y, &z));
1581   if (usecprow) { /* use compressed row format */
1582     if (zz != yy) PetscCall(PetscArraycpy(z, y, m));
1583     m    = a->compressedrow.nrows;
1584     ii   = a->compressedrow.i;
1585     ridx = a->compressedrow.rindex;
1586     for (i = 0; i < m; i++) {
1587       n   = ii[i + 1] - ii[i];
1588       aj  = a->j + ii[i];
1589       aa  = a_a + ii[i];
1590       sum = y[*ridx];
1591       PetscSparseDenseMaxDot(sum, x, aa, aj, n);
1592       z[*ridx++] = sum;
1593     }
1594   } else { /* do not use compressed row format */
1595     ii = a->i;
1596     for (i = 0; i < m; i++) {
1597       n   = ii[i + 1] - ii[i];
1598       aj  = a->j + ii[i];
1599       aa  = a_a + ii[i];
1600       sum = y[i];
1601       PetscSparseDenseMaxDot(sum, x, aa, aj, n);
1602       z[i] = sum;
1603     }
1604   }
1605   PetscCall(PetscLogFlops(2.0 * a->nz));
1606   PetscCall(VecRestoreArrayRead(xx, &x));
1607   PetscCall(VecRestoreArrayPair(yy, zz, &y, &z));
1608   PetscCall(MatSeqAIJRestoreArrayRead(A, &a_a));
1609   PetscFunctionReturn(0);
1610 }
1611 
1612 #include <../src/mat/impls/aij/seq/ftn-kernels/fmultadd.h>
1613 PetscErrorCode MatMultAdd_SeqAIJ(Mat A, Vec xx, Vec yy, Vec zz)
1614 {
1615   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1616   PetscScalar       *y, *z;
1617   const PetscScalar *x;
1618   const MatScalar   *aa, *a_a;
1619   const PetscInt    *aj, *ii, *ridx = NULL;
1620   PetscInt           m = A->rmap->n, n, i;
1621   PetscScalar        sum;
1622   PetscBool          usecprow = a->compressedrow.use;
1623 
1624   PetscFunctionBegin;
1625   if (a->inode.use && a->inode.checked) {
1626     PetscCall(MatMultAdd_SeqAIJ_Inode(A, xx, yy, zz));
1627     PetscFunctionReturn(0);
1628   }
1629   PetscCall(MatSeqAIJGetArrayRead(A, &a_a));
1630   PetscCall(VecGetArrayRead(xx, &x));
1631   PetscCall(VecGetArrayPair(yy, zz, &y, &z));
1632   if (usecprow) { /* use compressed row format */
1633     if (zz != yy) PetscCall(PetscArraycpy(z, y, m));
1634     m    = a->compressedrow.nrows;
1635     ii   = a->compressedrow.i;
1636     ridx = a->compressedrow.rindex;
1637     for (i = 0; i < m; i++) {
1638       n   = ii[i + 1] - ii[i];
1639       aj  = a->j + ii[i];
1640       aa  = a_a + ii[i];
1641       sum = y[*ridx];
1642       PetscSparseDensePlusDot(sum, x, aa, aj, n);
1643       z[*ridx++] = sum;
1644     }
1645   } else { /* do not use compressed row format */
1646     ii = a->i;
1647 #if defined(PETSC_USE_FORTRAN_KERNEL_MULTADDAIJ)
1648     aj = a->j;
1649     aa = a_a;
1650     fortranmultaddaij_(&m, x, ii, aj, aa, y, z);
1651 #else
1652     for (i = 0; i < m; i++) {
1653       n = ii[i + 1] - ii[i];
1654       aj = a->j + ii[i];
1655       aa = a_a + ii[i];
1656       sum = y[i];
1657       PetscSparseDensePlusDot(sum, x, aa, aj, n);
1658       z[i] = sum;
1659     }
1660 #endif
1661   }
1662   PetscCall(PetscLogFlops(2.0 * a->nz));
1663   PetscCall(VecRestoreArrayRead(xx, &x));
1664   PetscCall(VecRestoreArrayPair(yy, zz, &y, &z));
1665   PetscCall(MatSeqAIJRestoreArrayRead(A, &a_a));
1666   PetscFunctionReturn(0);
1667 }
1668 
1669 /*
1670      Adds diagonal pointers to sparse matrix structure.
1671 */
1672 PetscErrorCode MatMarkDiagonal_SeqAIJ(Mat A)
1673 {
1674   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1675   PetscInt    i, j, m = A->rmap->n;
1676   PetscBool   alreadySet = PETSC_TRUE;
1677 
1678   PetscFunctionBegin;
1679   if (!a->diag) {
1680     PetscCall(PetscMalloc1(m, &a->diag));
1681     alreadySet = PETSC_FALSE;
1682   }
1683   for (i = 0; i < A->rmap->n; i++) {
1684     /* If A's diagonal is already correctly set, this fast track enables cheap and repeated MatMarkDiagonal_SeqAIJ() calls */
1685     if (alreadySet) {
1686       PetscInt pos = a->diag[i];
1687       if (pos >= a->i[i] && pos < a->i[i + 1] && a->j[pos] == i) continue;
1688     }
1689 
1690     a->diag[i] = a->i[i + 1];
1691     for (j = a->i[i]; j < a->i[i + 1]; j++) {
1692       if (a->j[j] == i) {
1693         a->diag[i] = j;
1694         break;
1695       }
1696     }
1697   }
1698   PetscFunctionReturn(0);
1699 }
1700 
1701 PetscErrorCode MatShift_SeqAIJ(Mat A, PetscScalar v)
1702 {
1703   Mat_SeqAIJ     *a    = (Mat_SeqAIJ *)A->data;
1704   const PetscInt *diag = (const PetscInt *)a->diag;
1705   const PetscInt *ii   = (const PetscInt *)a->i;
1706   PetscInt        i, *mdiag = NULL;
1707   PetscInt        cnt = 0; /* how many diagonals are missing */
1708 
1709   PetscFunctionBegin;
1710   if (!A->preallocated || !a->nz) {
1711     PetscCall(MatSeqAIJSetPreallocation(A, 1, NULL));
1712     PetscCall(MatShift_Basic(A, v));
1713     PetscFunctionReturn(0);
1714   }
1715 
1716   if (a->diagonaldense) {
1717     cnt = 0;
1718   } else {
1719     PetscCall(PetscCalloc1(A->rmap->n, &mdiag));
1720     for (i = 0; i < A->rmap->n; i++) {
1721       if (i < A->cmap->n && diag[i] >= ii[i + 1]) { /* 'out of range' rows never have diagonals */
1722         cnt++;
1723         mdiag[i] = 1;
1724       }
1725     }
1726   }
1727   if (!cnt) {
1728     PetscCall(MatShift_Basic(A, v));
1729   } else {
1730     PetscScalar *olda = a->a; /* preserve pointers to current matrix nonzeros structure and values */
1731     PetscInt    *oldj = a->j, *oldi = a->i;
1732     PetscBool    singlemalloc = a->singlemalloc, free_a = a->free_a, free_ij = a->free_ij;
1733 
1734     a->a = NULL;
1735     a->j = NULL;
1736     a->i = NULL;
1737     /* increase the values in imax for each row where a diagonal is being inserted then reallocate the matrix data structures */
1738     for (i = 0; i < PetscMin(A->rmap->n, A->cmap->n); i++) a->imax[i] += mdiag[i];
1739     PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(A, 0, a->imax));
1740 
1741     /* copy old values into new matrix data structure */
1742     for (i = 0; i < A->rmap->n; i++) {
1743       PetscCall(MatSetValues(A, 1, &i, a->imax[i] - mdiag[i], &oldj[oldi[i]], &olda[oldi[i]], ADD_VALUES));
1744       if (i < A->cmap->n) PetscCall(MatSetValue(A, i, i, v, ADD_VALUES));
1745     }
1746     PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
1747     PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
1748     if (singlemalloc) {
1749       PetscCall(PetscFree3(olda, oldj, oldi));
1750     } else {
1751       if (free_a) PetscCall(PetscFree(olda));
1752       if (free_ij) PetscCall(PetscFree(oldj));
1753       if (free_ij) PetscCall(PetscFree(oldi));
1754     }
1755   }
1756   PetscCall(PetscFree(mdiag));
1757   a->diagonaldense = PETSC_TRUE;
1758   PetscFunctionReturn(0);
1759 }
1760 
1761 /*
1762      Checks for missing diagonals
1763 */
1764 PetscErrorCode MatMissingDiagonal_SeqAIJ(Mat A, PetscBool *missing, PetscInt *d)
1765 {
1766   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1767   PetscInt   *diag, *ii = a->i, i;
1768 
1769   PetscFunctionBegin;
1770   *missing = PETSC_FALSE;
1771   if (A->rmap->n > 0 && !ii) {
1772     *missing = PETSC_TRUE;
1773     if (d) *d = 0;
1774     PetscCall(PetscInfo(A, "Matrix has no entries therefore is missing diagonal\n"));
1775   } else {
1776     PetscInt n;
1777     n    = PetscMin(A->rmap->n, A->cmap->n);
1778     diag = a->diag;
1779     for (i = 0; i < n; i++) {
1780       if (diag[i] >= ii[i + 1]) {
1781         *missing = PETSC_TRUE;
1782         if (d) *d = i;
1783         PetscCall(PetscInfo(A, "Matrix is missing diagonal number %" PetscInt_FMT "\n", i));
1784         break;
1785       }
1786     }
1787   }
1788   PetscFunctionReturn(0);
1789 }
1790 
1791 #include <petscblaslapack.h>
1792 #include <petsc/private/kernels/blockinvert.h>
1793 
1794 /*
1795     Note that values is allocated externally by the PC and then passed into this routine
1796 */
1797 PetscErrorCode MatInvertVariableBlockDiagonal_SeqAIJ(Mat A, PetscInt nblocks, const PetscInt *bsizes, PetscScalar *diag)
1798 {
1799   PetscInt        n = A->rmap->n, i, ncnt = 0, *indx, j, bsizemax = 0, *v_pivots;
1800   PetscBool       allowzeropivot, zeropivotdetected = PETSC_FALSE;
1801   const PetscReal shift = 0.0;
1802   PetscInt        ipvt[5];
1803   PetscScalar     work[25], *v_work;
1804 
1805   PetscFunctionBegin;
1806   allowzeropivot = PetscNot(A->erroriffailure);
1807   for (i = 0; i < nblocks; i++) ncnt += bsizes[i];
1808   PetscCheck(ncnt == n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Total blocksizes %" PetscInt_FMT " doesn't match number matrix rows %" PetscInt_FMT, ncnt, n);
1809   for (i = 0; i < nblocks; i++) bsizemax = PetscMax(bsizemax, bsizes[i]);
1810   PetscCall(PetscMalloc1(bsizemax, &indx));
1811   if (bsizemax > 7) PetscCall(PetscMalloc2(bsizemax, &v_work, bsizemax, &v_pivots));
1812   ncnt = 0;
1813   for (i = 0; i < nblocks; i++) {
1814     for (j = 0; j < bsizes[i]; j++) indx[j] = ncnt + j;
1815     PetscCall(MatGetValues(A, bsizes[i], indx, bsizes[i], indx, diag));
1816     switch (bsizes[i]) {
1817     case 1:
1818       *diag = 1.0 / (*diag);
1819       break;
1820     case 2:
1821       PetscCall(PetscKernel_A_gets_inverse_A_2(diag, shift, allowzeropivot, &zeropivotdetected));
1822       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1823       PetscCall(PetscKernel_A_gets_transpose_A_2(diag));
1824       break;
1825     case 3:
1826       PetscCall(PetscKernel_A_gets_inverse_A_3(diag, shift, allowzeropivot, &zeropivotdetected));
1827       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1828       PetscCall(PetscKernel_A_gets_transpose_A_3(diag));
1829       break;
1830     case 4:
1831       PetscCall(PetscKernel_A_gets_inverse_A_4(diag, shift, allowzeropivot, &zeropivotdetected));
1832       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1833       PetscCall(PetscKernel_A_gets_transpose_A_4(diag));
1834       break;
1835     case 5:
1836       PetscCall(PetscKernel_A_gets_inverse_A_5(diag, ipvt, work, shift, allowzeropivot, &zeropivotdetected));
1837       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1838       PetscCall(PetscKernel_A_gets_transpose_A_5(diag));
1839       break;
1840     case 6:
1841       PetscCall(PetscKernel_A_gets_inverse_A_6(diag, shift, allowzeropivot, &zeropivotdetected));
1842       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1843       PetscCall(PetscKernel_A_gets_transpose_A_6(diag));
1844       break;
1845     case 7:
1846       PetscCall(PetscKernel_A_gets_inverse_A_7(diag, shift, allowzeropivot, &zeropivotdetected));
1847       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1848       PetscCall(PetscKernel_A_gets_transpose_A_7(diag));
1849       break;
1850     default:
1851       PetscCall(PetscKernel_A_gets_inverse_A(bsizes[i], diag, v_pivots, v_work, allowzeropivot, &zeropivotdetected));
1852       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1853       PetscCall(PetscKernel_A_gets_transpose_A_N(diag, bsizes[i]));
1854     }
1855     ncnt += bsizes[i];
1856     diag += bsizes[i] * bsizes[i];
1857   }
1858   if (bsizemax > 7) PetscCall(PetscFree2(v_work, v_pivots));
1859   PetscCall(PetscFree(indx));
1860   PetscFunctionReturn(0);
1861 }
1862 
1863 /*
1864    Negative shift indicates do not generate an error if there is a zero diagonal, just invert it anyways
1865 */
1866 PetscErrorCode MatInvertDiagonal_SeqAIJ(Mat A, PetscScalar omega, PetscScalar fshift)
1867 {
1868   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
1869   PetscInt         i, *diag, m = A->rmap->n;
1870   const MatScalar *v;
1871   PetscScalar     *idiag, *mdiag;
1872 
1873   PetscFunctionBegin;
1874   if (a->idiagvalid) PetscFunctionReturn(0);
1875   PetscCall(MatMarkDiagonal_SeqAIJ(A));
1876   diag = a->diag;
1877   if (!a->idiag) { PetscCall(PetscMalloc3(m, &a->idiag, m, &a->mdiag, m, &a->ssor_work)); }
1878 
1879   mdiag = a->mdiag;
1880   idiag = a->idiag;
1881   PetscCall(MatSeqAIJGetArrayRead(A, &v));
1882   if (omega == 1.0 && PetscRealPart(fshift) <= 0.0) {
1883     for (i = 0; i < m; i++) {
1884       mdiag[i] = v[diag[i]];
1885       if (!PetscAbsScalar(mdiag[i])) { /* zero diagonal */
1886         if (PetscRealPart(fshift)) {
1887           PetscCall(PetscInfo(A, "Zero diagonal on row %" PetscInt_FMT "\n", i));
1888           A->factorerrortype             = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1889           A->factorerror_zeropivot_value = 0.0;
1890           A->factorerror_zeropivot_row   = i;
1891         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Zero diagonal on row %" PetscInt_FMT, i);
1892       }
1893       idiag[i] = 1.0 / v[diag[i]];
1894     }
1895     PetscCall(PetscLogFlops(m));
1896   } else {
1897     for (i = 0; i < m; i++) {
1898       mdiag[i] = v[diag[i]];
1899       idiag[i] = omega / (fshift + v[diag[i]]);
1900     }
1901     PetscCall(PetscLogFlops(2.0 * m));
1902   }
1903   a->idiagvalid = PETSC_TRUE;
1904   PetscCall(MatSeqAIJRestoreArrayRead(A, &v));
1905   PetscFunctionReturn(0);
1906 }
1907 
1908 #include <../src/mat/impls/aij/seq/ftn-kernels/frelax.h>
1909 PetscErrorCode MatSOR_SeqAIJ(Mat A, Vec bb, PetscReal omega, MatSORType flag, PetscReal fshift, PetscInt its, PetscInt lits, Vec xx)
1910 {
1911   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1912   PetscScalar       *x, d, sum, *t, scale;
1913   const MatScalar   *v, *idiag = NULL, *mdiag, *aa;
1914   const PetscScalar *b, *bs, *xb, *ts;
1915   PetscInt           n, m = A->rmap->n, i;
1916   const PetscInt    *idx, *diag;
1917 
1918   PetscFunctionBegin;
1919   if (a->inode.use && a->inode.checked && omega == 1.0 && fshift == 0.0) {
1920     PetscCall(MatSOR_SeqAIJ_Inode(A, bb, omega, flag, fshift, its, lits, xx));
1921     PetscFunctionReturn(0);
1922   }
1923   its = its * lits;
1924 
1925   if (fshift != a->fshift || omega != a->omega) a->idiagvalid = PETSC_FALSE; /* must recompute idiag[] */
1926   if (!a->idiagvalid) PetscCall(MatInvertDiagonal_SeqAIJ(A, omega, fshift));
1927   a->fshift = fshift;
1928   a->omega  = omega;
1929 
1930   diag  = a->diag;
1931   t     = a->ssor_work;
1932   idiag = a->idiag;
1933   mdiag = a->mdiag;
1934 
1935   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
1936   PetscCall(VecGetArray(xx, &x));
1937   PetscCall(VecGetArrayRead(bb, &b));
1938   /* We count flops by assuming the upper triangular and lower triangular parts have the same number of nonzeros */
1939   if (flag == SOR_APPLY_UPPER) {
1940     /* apply (U + D/omega) to the vector */
1941     bs = b;
1942     for (i = 0; i < m; i++) {
1943       d   = fshift + mdiag[i];
1944       n   = a->i[i + 1] - diag[i] - 1;
1945       idx = a->j + diag[i] + 1;
1946       v   = aa + diag[i] + 1;
1947       sum = b[i] * d / omega;
1948       PetscSparseDensePlusDot(sum, bs, v, idx, n);
1949       x[i] = sum;
1950     }
1951     PetscCall(VecRestoreArray(xx, &x));
1952     PetscCall(VecRestoreArrayRead(bb, &b));
1953     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1954     PetscCall(PetscLogFlops(a->nz));
1955     PetscFunctionReturn(0);
1956   }
1957 
1958   PetscCheck(flag != SOR_APPLY_LOWER, PETSC_COMM_SELF, PETSC_ERR_SUP, "SOR_APPLY_LOWER is not implemented");
1959   if (flag & SOR_EISENSTAT) {
1960     /* Let  A = L + U + D; where L is lower triangular,
1961     U is upper triangular, E = D/omega; This routine applies
1962 
1963             (L + E)^{-1} A (U + E)^{-1}
1964 
1965     to a vector efficiently using Eisenstat's trick.
1966     */
1967     scale = (2.0 / omega) - 1.0;
1968 
1969     /*  x = (E + U)^{-1} b */
1970     for (i = m - 1; i >= 0; i--) {
1971       n   = a->i[i + 1] - diag[i] - 1;
1972       idx = a->j + diag[i] + 1;
1973       v   = aa + diag[i] + 1;
1974       sum = b[i];
1975       PetscSparseDenseMinusDot(sum, x, v, idx, n);
1976       x[i] = sum * idiag[i];
1977     }
1978 
1979     /*  t = b - (2*E - D)x */
1980     v = aa;
1981     for (i = 0; i < m; i++) t[i] = b[i] - scale * (v[*diag++]) * x[i];
1982 
1983     /*  t = (E + L)^{-1}t */
1984     ts   = t;
1985     diag = a->diag;
1986     for (i = 0; i < m; i++) {
1987       n   = diag[i] - a->i[i];
1988       idx = a->j + a->i[i];
1989       v   = aa + a->i[i];
1990       sum = t[i];
1991       PetscSparseDenseMinusDot(sum, ts, v, idx, n);
1992       t[i] = sum * idiag[i];
1993       /*  x = x + t */
1994       x[i] += t[i];
1995     }
1996 
1997     PetscCall(PetscLogFlops(6.0 * m - 1 + 2.0 * a->nz));
1998     PetscCall(VecRestoreArray(xx, &x));
1999     PetscCall(VecRestoreArrayRead(bb, &b));
2000     PetscFunctionReturn(0);
2001   }
2002   if (flag & SOR_ZERO_INITIAL_GUESS) {
2003     if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP) {
2004       for (i = 0; i < m; i++) {
2005         n   = diag[i] - a->i[i];
2006         idx = a->j + a->i[i];
2007         v   = aa + a->i[i];
2008         sum = b[i];
2009         PetscSparseDenseMinusDot(sum, x, v, idx, n);
2010         t[i] = sum;
2011         x[i] = sum * idiag[i];
2012       }
2013       xb = t;
2014       PetscCall(PetscLogFlops(a->nz));
2015     } else xb = b;
2016     if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP) {
2017       for (i = m - 1; i >= 0; i--) {
2018         n   = a->i[i + 1] - diag[i] - 1;
2019         idx = a->j + diag[i] + 1;
2020         v   = aa + diag[i] + 1;
2021         sum = xb[i];
2022         PetscSparseDenseMinusDot(sum, x, v, idx, n);
2023         if (xb == b) {
2024           x[i] = sum * idiag[i];
2025         } else {
2026           x[i] = (1 - omega) * x[i] + sum * idiag[i]; /* omega in idiag */
2027         }
2028       }
2029       PetscCall(PetscLogFlops(a->nz)); /* assumes 1/2 in upper */
2030     }
2031     its--;
2032   }
2033   while (its--) {
2034     if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP) {
2035       for (i = 0; i < m; i++) {
2036         /* lower */
2037         n   = diag[i] - a->i[i];
2038         idx = a->j + a->i[i];
2039         v   = aa + a->i[i];
2040         sum = b[i];
2041         PetscSparseDenseMinusDot(sum, x, v, idx, n);
2042         t[i] = sum; /* save application of the lower-triangular part */
2043         /* upper */
2044         n   = a->i[i + 1] - diag[i] - 1;
2045         idx = a->j + diag[i] + 1;
2046         v   = aa + diag[i] + 1;
2047         PetscSparseDenseMinusDot(sum, x, v, idx, n);
2048         x[i] = (1. - omega) * x[i] + sum * idiag[i]; /* omega in idiag */
2049       }
2050       xb = t;
2051       PetscCall(PetscLogFlops(2.0 * a->nz));
2052     } else xb = b;
2053     if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP) {
2054       for (i = m - 1; i >= 0; i--) {
2055         sum = xb[i];
2056         if (xb == b) {
2057           /* whole matrix (no checkpointing available) */
2058           n   = a->i[i + 1] - a->i[i];
2059           idx = a->j + a->i[i];
2060           v   = aa + a->i[i];
2061           PetscSparseDenseMinusDot(sum, x, v, idx, n);
2062           x[i] = (1. - omega) * x[i] + (sum + mdiag[i] * x[i]) * idiag[i];
2063         } else { /* lower-triangular part has been saved, so only apply upper-triangular */
2064           n   = a->i[i + 1] - diag[i] - 1;
2065           idx = a->j + diag[i] + 1;
2066           v   = aa + diag[i] + 1;
2067           PetscSparseDenseMinusDot(sum, x, v, idx, n);
2068           x[i] = (1. - omega) * x[i] + sum * idiag[i]; /* omega in idiag */
2069         }
2070       }
2071       if (xb == b) {
2072         PetscCall(PetscLogFlops(2.0 * a->nz));
2073       } else {
2074         PetscCall(PetscLogFlops(a->nz)); /* assumes 1/2 in upper */
2075       }
2076     }
2077   }
2078   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2079   PetscCall(VecRestoreArray(xx, &x));
2080   PetscCall(VecRestoreArrayRead(bb, &b));
2081   PetscFunctionReturn(0);
2082 }
2083 
2084 PetscErrorCode MatGetInfo_SeqAIJ(Mat A, MatInfoType flag, MatInfo *info)
2085 {
2086   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
2087 
2088   PetscFunctionBegin;
2089   info->block_size   = 1.0;
2090   info->nz_allocated = a->maxnz;
2091   info->nz_used      = a->nz;
2092   info->nz_unneeded  = (a->maxnz - a->nz);
2093   info->assemblies   = A->num_ass;
2094   info->mallocs      = A->info.mallocs;
2095   info->memory       = 0; /* REVIEW ME */
2096   if (A->factortype) {
2097     info->fill_ratio_given  = A->info.fill_ratio_given;
2098     info->fill_ratio_needed = A->info.fill_ratio_needed;
2099     info->factor_mallocs    = A->info.factor_mallocs;
2100   } else {
2101     info->fill_ratio_given  = 0;
2102     info->fill_ratio_needed = 0;
2103     info->factor_mallocs    = 0;
2104   }
2105   PetscFunctionReturn(0);
2106 }
2107 
2108 PetscErrorCode MatZeroRows_SeqAIJ(Mat A, PetscInt N, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
2109 {
2110   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2111   PetscInt           i, m = A->rmap->n - 1;
2112   const PetscScalar *xx;
2113   PetscScalar       *bb, *aa;
2114   PetscInt           d = 0;
2115 
2116   PetscFunctionBegin;
2117   if (x && b) {
2118     PetscCall(VecGetArrayRead(x, &xx));
2119     PetscCall(VecGetArray(b, &bb));
2120     for (i = 0; i < N; i++) {
2121       PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2122       if (rows[i] >= A->cmap->n) continue;
2123       bb[rows[i]] = diag * xx[rows[i]];
2124     }
2125     PetscCall(VecRestoreArrayRead(x, &xx));
2126     PetscCall(VecRestoreArray(b, &bb));
2127   }
2128 
2129   PetscCall(MatSeqAIJGetArray(A, &aa));
2130   if (a->keepnonzeropattern) {
2131     for (i = 0; i < N; i++) {
2132       PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2133       PetscCall(PetscArrayzero(&aa[a->i[rows[i]]], a->ilen[rows[i]]));
2134     }
2135     if (diag != 0.0) {
2136       for (i = 0; i < N; i++) {
2137         d = rows[i];
2138         if (rows[i] >= A->cmap->n) continue;
2139         PetscCheck(a->diag[d] < a->i[d + 1], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Matrix is missing diagonal entry in the zeroed row %" PetscInt_FMT, d);
2140       }
2141       for (i = 0; i < N; i++) {
2142         if (rows[i] >= A->cmap->n) continue;
2143         aa[a->diag[rows[i]]] = diag;
2144       }
2145     }
2146   } else {
2147     if (diag != 0.0) {
2148       for (i = 0; i < N; i++) {
2149         PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2150         if (a->ilen[rows[i]] > 0) {
2151           if (rows[i] >= A->cmap->n) {
2152             a->ilen[rows[i]] = 0;
2153           } else {
2154             a->ilen[rows[i]]    = 1;
2155             aa[a->i[rows[i]]]   = diag;
2156             a->j[a->i[rows[i]]] = rows[i];
2157           }
2158         } else if (rows[i] < A->cmap->n) { /* in case row was completely empty */
2159           PetscCall(MatSetValues_SeqAIJ(A, 1, &rows[i], 1, &rows[i], &diag, INSERT_VALUES));
2160         }
2161       }
2162     } else {
2163       for (i = 0; i < N; i++) {
2164         PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2165         a->ilen[rows[i]] = 0;
2166       }
2167     }
2168     A->nonzerostate++;
2169   }
2170   PetscCall(MatSeqAIJRestoreArray(A, &aa));
2171   PetscUseTypeMethod(A, assemblyend, MAT_FINAL_ASSEMBLY);
2172   PetscFunctionReturn(0);
2173 }
2174 
2175 PetscErrorCode MatZeroRowsColumns_SeqAIJ(Mat A, PetscInt N, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
2176 {
2177   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2178   PetscInt           i, j, m = A->rmap->n - 1, d = 0;
2179   PetscBool          missing, *zeroed, vecs = PETSC_FALSE;
2180   const PetscScalar *xx;
2181   PetscScalar       *bb, *aa;
2182 
2183   PetscFunctionBegin;
2184   if (!N) PetscFunctionReturn(0);
2185   PetscCall(MatSeqAIJGetArray(A, &aa));
2186   if (x && b) {
2187     PetscCall(VecGetArrayRead(x, &xx));
2188     PetscCall(VecGetArray(b, &bb));
2189     vecs = PETSC_TRUE;
2190   }
2191   PetscCall(PetscCalloc1(A->rmap->n, &zeroed));
2192   for (i = 0; i < N; i++) {
2193     PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2194     PetscCall(PetscArrayzero(&aa[a->i[rows[i]]], a->ilen[rows[i]]));
2195 
2196     zeroed[rows[i]] = PETSC_TRUE;
2197   }
2198   for (i = 0; i < A->rmap->n; i++) {
2199     if (!zeroed[i]) {
2200       for (j = a->i[i]; j < a->i[i + 1]; j++) {
2201         if (a->j[j] < A->rmap->n && zeroed[a->j[j]]) {
2202           if (vecs) bb[i] -= aa[j] * xx[a->j[j]];
2203           aa[j] = 0.0;
2204         }
2205       }
2206     } else if (vecs && i < A->cmap->N) bb[i] = diag * xx[i];
2207   }
2208   if (x && b) {
2209     PetscCall(VecRestoreArrayRead(x, &xx));
2210     PetscCall(VecRestoreArray(b, &bb));
2211   }
2212   PetscCall(PetscFree(zeroed));
2213   if (diag != 0.0) {
2214     PetscCall(MatMissingDiagonal_SeqAIJ(A, &missing, &d));
2215     if (missing) {
2216       for (i = 0; i < N; i++) {
2217         if (rows[i] >= A->cmap->N) continue;
2218         PetscCheck(!a->nonew || rows[i] < d, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Matrix is missing diagonal entry in row %" PetscInt_FMT " (%" PetscInt_FMT ")", d, rows[i]);
2219         PetscCall(MatSetValues_SeqAIJ(A, 1, &rows[i], 1, &rows[i], &diag, INSERT_VALUES));
2220       }
2221     } else {
2222       for (i = 0; i < N; i++) aa[a->diag[rows[i]]] = diag;
2223     }
2224   }
2225   PetscCall(MatSeqAIJRestoreArray(A, &aa));
2226   PetscUseTypeMethod(A, assemblyend, MAT_FINAL_ASSEMBLY);
2227   PetscFunctionReturn(0);
2228 }
2229 
2230 PetscErrorCode MatGetRow_SeqAIJ(Mat A, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v)
2231 {
2232   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2233   const PetscScalar *aa;
2234   PetscInt          *itmp;
2235 
2236   PetscFunctionBegin;
2237   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
2238   *nz = a->i[row + 1] - a->i[row];
2239   if (v) *v = (PetscScalar *)(aa + a->i[row]);
2240   if (idx) {
2241     itmp = a->j + a->i[row];
2242     if (*nz) *idx = itmp;
2243     else *idx = NULL;
2244   }
2245   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2246   PetscFunctionReturn(0);
2247 }
2248 
2249 PetscErrorCode MatRestoreRow_SeqAIJ(Mat A, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v)
2250 {
2251   PetscFunctionBegin;
2252   if (nz) *nz = 0;
2253   if (idx) *idx = NULL;
2254   if (v) *v = NULL;
2255   PetscFunctionReturn(0);
2256 }
2257 
2258 PetscErrorCode MatNorm_SeqAIJ(Mat A, NormType type, PetscReal *nrm)
2259 {
2260   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
2261   const MatScalar *v;
2262   PetscReal        sum = 0.0;
2263   PetscInt         i, j;
2264 
2265   PetscFunctionBegin;
2266   PetscCall(MatSeqAIJGetArrayRead(A, &v));
2267   if (type == NORM_FROBENIUS) {
2268 #if defined(PETSC_USE_REAL___FP16)
2269     PetscBLASInt one = 1, nz = a->nz;
2270     PetscCallBLAS("BLASnrm2", *nrm = BLASnrm2_(&nz, v, &one));
2271 #else
2272     for (i = 0; i < a->nz; i++) {
2273       sum += PetscRealPart(PetscConj(*v) * (*v));
2274       v++;
2275     }
2276     *nrm = PetscSqrtReal(sum);
2277 #endif
2278     PetscCall(PetscLogFlops(2.0 * a->nz));
2279   } else if (type == NORM_1) {
2280     PetscReal *tmp;
2281     PetscInt  *jj = a->j;
2282     PetscCall(PetscCalloc1(A->cmap->n + 1, &tmp));
2283     *nrm = 0.0;
2284     for (j = 0; j < a->nz; j++) {
2285       tmp[*jj++] += PetscAbsScalar(*v);
2286       v++;
2287     }
2288     for (j = 0; j < A->cmap->n; j++) {
2289       if (tmp[j] > *nrm) *nrm = tmp[j];
2290     }
2291     PetscCall(PetscFree(tmp));
2292     PetscCall(PetscLogFlops(PetscMax(a->nz - 1, 0)));
2293   } else if (type == NORM_INFINITY) {
2294     *nrm = 0.0;
2295     for (j = 0; j < A->rmap->n; j++) {
2296       const PetscScalar *v2 = v + a->i[j];
2297       sum                   = 0.0;
2298       for (i = 0; i < a->i[j + 1] - a->i[j]; i++) {
2299         sum += PetscAbsScalar(*v2);
2300         v2++;
2301       }
2302       if (sum > *nrm) *nrm = sum;
2303     }
2304     PetscCall(PetscLogFlops(PetscMax(a->nz - 1, 0)));
2305   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "No support for two norm");
2306   PetscCall(MatSeqAIJRestoreArrayRead(A, &v));
2307   PetscFunctionReturn(0);
2308 }
2309 
2310 PetscErrorCode MatIsTranspose_SeqAIJ(Mat A, Mat B, PetscReal tol, PetscBool *f)
2311 {
2312   Mat_SeqAIJ      *aij = (Mat_SeqAIJ *)A->data, *bij = (Mat_SeqAIJ *)B->data;
2313   PetscInt        *adx, *bdx, *aii, *bii, *aptr, *bptr;
2314   const MatScalar *va, *vb;
2315   PetscInt         ma, na, mb, nb, i;
2316 
2317   PetscFunctionBegin;
2318   PetscCall(MatGetSize(A, &ma, &na));
2319   PetscCall(MatGetSize(B, &mb, &nb));
2320   if (ma != nb || na != mb) {
2321     *f = PETSC_FALSE;
2322     PetscFunctionReturn(0);
2323   }
2324   PetscCall(MatSeqAIJGetArrayRead(A, &va));
2325   PetscCall(MatSeqAIJGetArrayRead(B, &vb));
2326   aii = aij->i;
2327   bii = bij->i;
2328   adx = aij->j;
2329   bdx = bij->j;
2330   PetscCall(PetscMalloc1(ma, &aptr));
2331   PetscCall(PetscMalloc1(mb, &bptr));
2332   for (i = 0; i < ma; i++) aptr[i] = aii[i];
2333   for (i = 0; i < mb; i++) bptr[i] = bii[i];
2334 
2335   *f = PETSC_TRUE;
2336   for (i = 0; i < ma; i++) {
2337     while (aptr[i] < aii[i + 1]) {
2338       PetscInt    idc, idr;
2339       PetscScalar vc, vr;
2340       /* column/row index/value */
2341       idc = adx[aptr[i]];
2342       idr = bdx[bptr[idc]];
2343       vc  = va[aptr[i]];
2344       vr  = vb[bptr[idc]];
2345       if (i != idr || PetscAbsScalar(vc - vr) > tol) {
2346         *f = PETSC_FALSE;
2347         goto done;
2348       } else {
2349         aptr[i]++;
2350         if (B || i != idc) bptr[idc]++;
2351       }
2352     }
2353   }
2354 done:
2355   PetscCall(PetscFree(aptr));
2356   PetscCall(PetscFree(bptr));
2357   PetscCall(MatSeqAIJRestoreArrayRead(A, &va));
2358   PetscCall(MatSeqAIJRestoreArrayRead(B, &vb));
2359   PetscFunctionReturn(0);
2360 }
2361 
2362 PetscErrorCode MatIsHermitianTranspose_SeqAIJ(Mat A, Mat B, PetscReal tol, PetscBool *f)
2363 {
2364   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data, *bij = (Mat_SeqAIJ *)B->data;
2365   PetscInt   *adx, *bdx, *aii, *bii, *aptr, *bptr;
2366   MatScalar  *va, *vb;
2367   PetscInt    ma, na, mb, nb, i;
2368 
2369   PetscFunctionBegin;
2370   PetscCall(MatGetSize(A, &ma, &na));
2371   PetscCall(MatGetSize(B, &mb, &nb));
2372   if (ma != nb || na != mb) {
2373     *f = PETSC_FALSE;
2374     PetscFunctionReturn(0);
2375   }
2376   aii = aij->i;
2377   bii = bij->i;
2378   adx = aij->j;
2379   bdx = bij->j;
2380   va  = aij->a;
2381   vb  = bij->a;
2382   PetscCall(PetscMalloc1(ma, &aptr));
2383   PetscCall(PetscMalloc1(mb, &bptr));
2384   for (i = 0; i < ma; i++) aptr[i] = aii[i];
2385   for (i = 0; i < mb; i++) bptr[i] = bii[i];
2386 
2387   *f = PETSC_TRUE;
2388   for (i = 0; i < ma; i++) {
2389     while (aptr[i] < aii[i + 1]) {
2390       PetscInt    idc, idr;
2391       PetscScalar vc, vr;
2392       /* column/row index/value */
2393       idc = adx[aptr[i]];
2394       idr = bdx[bptr[idc]];
2395       vc  = va[aptr[i]];
2396       vr  = vb[bptr[idc]];
2397       if (i != idr || PetscAbsScalar(vc - PetscConj(vr)) > tol) {
2398         *f = PETSC_FALSE;
2399         goto done;
2400       } else {
2401         aptr[i]++;
2402         if (B || i != idc) bptr[idc]++;
2403       }
2404     }
2405   }
2406 done:
2407   PetscCall(PetscFree(aptr));
2408   PetscCall(PetscFree(bptr));
2409   PetscFunctionReturn(0);
2410 }
2411 
2412 PetscErrorCode MatIsSymmetric_SeqAIJ(Mat A, PetscReal tol, PetscBool *f)
2413 {
2414   PetscFunctionBegin;
2415   PetscCall(MatIsTranspose_SeqAIJ(A, A, tol, f));
2416   PetscFunctionReturn(0);
2417 }
2418 
2419 PetscErrorCode MatIsHermitian_SeqAIJ(Mat A, PetscReal tol, PetscBool *f)
2420 {
2421   PetscFunctionBegin;
2422   PetscCall(MatIsHermitianTranspose_SeqAIJ(A, A, tol, f));
2423   PetscFunctionReturn(0);
2424 }
2425 
2426 PetscErrorCode MatDiagonalScale_SeqAIJ(Mat A, Vec ll, Vec rr)
2427 {
2428   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2429   const PetscScalar *l, *r;
2430   PetscScalar        x;
2431   MatScalar         *v;
2432   PetscInt           i, j, m = A->rmap->n, n = A->cmap->n, M, nz = a->nz;
2433   const PetscInt    *jj;
2434 
2435   PetscFunctionBegin;
2436   if (ll) {
2437     /* The local size is used so that VecMPI can be passed to this routine
2438        by MatDiagonalScale_MPIAIJ */
2439     PetscCall(VecGetLocalSize(ll, &m));
2440     PetscCheck(m == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Left scaling vector wrong length");
2441     PetscCall(VecGetArrayRead(ll, &l));
2442     PetscCall(MatSeqAIJGetArray(A, &v));
2443     for (i = 0; i < m; i++) {
2444       x = l[i];
2445       M = a->i[i + 1] - a->i[i];
2446       for (j = 0; j < M; j++) (*v++) *= x;
2447     }
2448     PetscCall(VecRestoreArrayRead(ll, &l));
2449     PetscCall(PetscLogFlops(nz));
2450     PetscCall(MatSeqAIJRestoreArray(A, &v));
2451   }
2452   if (rr) {
2453     PetscCall(VecGetLocalSize(rr, &n));
2454     PetscCheck(n == A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Right scaling vector wrong length");
2455     PetscCall(VecGetArrayRead(rr, &r));
2456     PetscCall(MatSeqAIJGetArray(A, &v));
2457     jj = a->j;
2458     for (i = 0; i < nz; i++) (*v++) *= r[*jj++];
2459     PetscCall(MatSeqAIJRestoreArray(A, &v));
2460     PetscCall(VecRestoreArrayRead(rr, &r));
2461     PetscCall(PetscLogFlops(nz));
2462   }
2463   PetscCall(MatSeqAIJInvalidateDiagonal(A));
2464   PetscFunctionReturn(0);
2465 }
2466 
2467 PetscErrorCode MatCreateSubMatrix_SeqAIJ(Mat A, IS isrow, IS iscol, PetscInt csize, MatReuse scall, Mat *B)
2468 {
2469   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data, *c;
2470   PetscInt          *smap, i, k, kstart, kend, oldcols = A->cmap->n, *lens;
2471   PetscInt           row, mat_i, *mat_j, tcol, first, step, *mat_ilen, sum, lensi;
2472   const PetscInt    *irow, *icol;
2473   const PetscScalar *aa;
2474   PetscInt           nrows, ncols;
2475   PetscInt          *starts, *j_new, *i_new, *aj = a->j, *ai = a->i, ii, *ailen = a->ilen;
2476   MatScalar         *a_new, *mat_a;
2477   Mat                C;
2478   PetscBool          stride;
2479 
2480   PetscFunctionBegin;
2481   PetscCall(ISGetIndices(isrow, &irow));
2482   PetscCall(ISGetLocalSize(isrow, &nrows));
2483   PetscCall(ISGetLocalSize(iscol, &ncols));
2484 
2485   PetscCall(PetscObjectTypeCompare((PetscObject)iscol, ISSTRIDE, &stride));
2486   if (stride) {
2487     PetscCall(ISStrideGetInfo(iscol, &first, &step));
2488   } else {
2489     first = 0;
2490     step  = 0;
2491   }
2492   if (stride && step == 1) {
2493     /* special case of contiguous rows */
2494     PetscCall(PetscMalloc2(nrows, &lens, nrows, &starts));
2495     /* loop over new rows determining lens and starting points */
2496     for (i = 0; i < nrows; i++) {
2497       kstart    = ai[irow[i]];
2498       kend      = kstart + ailen[irow[i]];
2499       starts[i] = kstart;
2500       for (k = kstart; k < kend; k++) {
2501         if (aj[k] >= first) {
2502           starts[i] = k;
2503           break;
2504         }
2505       }
2506       sum = 0;
2507       while (k < kend) {
2508         if (aj[k++] >= first + ncols) break;
2509         sum++;
2510       }
2511       lens[i] = sum;
2512     }
2513     /* create submatrix */
2514     if (scall == MAT_REUSE_MATRIX) {
2515       PetscInt n_cols, n_rows;
2516       PetscCall(MatGetSize(*B, &n_rows, &n_cols));
2517       PetscCheck(n_rows == nrows && n_cols == ncols, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Reused submatrix wrong size");
2518       PetscCall(MatZeroEntries(*B));
2519       C = *B;
2520     } else {
2521       PetscInt rbs, cbs;
2522       PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2523       PetscCall(MatSetSizes(C, nrows, ncols, PETSC_DETERMINE, PETSC_DETERMINE));
2524       PetscCall(ISGetBlockSize(isrow, &rbs));
2525       PetscCall(ISGetBlockSize(iscol, &cbs));
2526       PetscCall(MatSetBlockSizes(C, rbs, cbs));
2527       PetscCall(MatSetType(C, ((PetscObject)A)->type_name));
2528       PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(C, 0, lens));
2529     }
2530     c = (Mat_SeqAIJ *)C->data;
2531 
2532     /* loop over rows inserting into submatrix */
2533     a_new = c->a;
2534     j_new = c->j;
2535     i_new = c->i;
2536     PetscCall(MatSeqAIJGetArrayRead(A, &aa));
2537     for (i = 0; i < nrows; i++) {
2538       ii    = starts[i];
2539       lensi = lens[i];
2540       for (k = 0; k < lensi; k++) *j_new++ = aj[ii + k] - first;
2541       PetscCall(PetscArraycpy(a_new, aa + starts[i], lensi));
2542       a_new += lensi;
2543       i_new[i + 1] = i_new[i] + lensi;
2544       c->ilen[i]   = lensi;
2545     }
2546     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2547     PetscCall(PetscFree2(lens, starts));
2548   } else {
2549     PetscCall(ISGetIndices(iscol, &icol));
2550     PetscCall(PetscCalloc1(oldcols, &smap));
2551     PetscCall(PetscMalloc1(1 + nrows, &lens));
2552     for (i = 0; i < ncols; i++) {
2553       PetscCheck(icol[i] < oldcols, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Requesting column beyond largest column icol[%" PetscInt_FMT "] %" PetscInt_FMT " >= A->cmap->n %" PetscInt_FMT, i, icol[i], oldcols);
2554       smap[icol[i]] = i + 1;
2555     }
2556 
2557     /* determine lens of each row */
2558     for (i = 0; i < nrows; i++) {
2559       kstart  = ai[irow[i]];
2560       kend    = kstart + a->ilen[irow[i]];
2561       lens[i] = 0;
2562       for (k = kstart; k < kend; k++) {
2563         if (smap[aj[k]]) lens[i]++;
2564       }
2565     }
2566     /* Create and fill new matrix */
2567     if (scall == MAT_REUSE_MATRIX) {
2568       PetscBool equal;
2569 
2570       c = (Mat_SeqAIJ *)((*B)->data);
2571       PetscCheck((*B)->rmap->n == nrows && (*B)->cmap->n == ncols, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Cannot reuse matrix. wrong size");
2572       PetscCall(PetscArraycmp(c->ilen, lens, (*B)->rmap->n, &equal));
2573       PetscCheck(equal, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Cannot reuse matrix. wrong no of nonzeros");
2574       PetscCall(PetscArrayzero(c->ilen, (*B)->rmap->n));
2575       C = *B;
2576     } else {
2577       PetscInt rbs, cbs;
2578       PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2579       PetscCall(MatSetSizes(C, nrows, ncols, PETSC_DETERMINE, PETSC_DETERMINE));
2580       PetscCall(ISGetBlockSize(isrow, &rbs));
2581       PetscCall(ISGetBlockSize(iscol, &cbs));
2582       PetscCall(MatSetBlockSizes(C, rbs, cbs));
2583       PetscCall(MatSetType(C, ((PetscObject)A)->type_name));
2584       PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(C, 0, lens));
2585     }
2586     PetscCall(MatSeqAIJGetArrayRead(A, &aa));
2587     c = (Mat_SeqAIJ *)(C->data);
2588     for (i = 0; i < nrows; i++) {
2589       row      = irow[i];
2590       kstart   = ai[row];
2591       kend     = kstart + a->ilen[row];
2592       mat_i    = c->i[i];
2593       mat_j    = c->j + mat_i;
2594       mat_a    = c->a + mat_i;
2595       mat_ilen = c->ilen + i;
2596       for (k = kstart; k < kend; k++) {
2597         if ((tcol = smap[a->j[k]])) {
2598           *mat_j++ = tcol - 1;
2599           *mat_a++ = aa[k];
2600           (*mat_ilen)++;
2601         }
2602       }
2603     }
2604     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2605     /* Free work space */
2606     PetscCall(ISRestoreIndices(iscol, &icol));
2607     PetscCall(PetscFree(smap));
2608     PetscCall(PetscFree(lens));
2609     /* sort */
2610     for (i = 0; i < nrows; i++) {
2611       PetscInt ilen;
2612 
2613       mat_i = c->i[i];
2614       mat_j = c->j + mat_i;
2615       mat_a = c->a + mat_i;
2616       ilen  = c->ilen[i];
2617       PetscCall(PetscSortIntWithScalarArray(ilen, mat_j, mat_a));
2618     }
2619   }
2620 #if defined(PETSC_HAVE_DEVICE)
2621   PetscCall(MatBindToCPU(C, A->boundtocpu));
2622 #endif
2623   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2624   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2625 
2626   PetscCall(ISRestoreIndices(isrow, &irow));
2627   *B = C;
2628   PetscFunctionReturn(0);
2629 }
2630 
2631 PetscErrorCode MatGetMultiProcBlock_SeqAIJ(Mat mat, MPI_Comm subComm, MatReuse scall, Mat *subMat)
2632 {
2633   Mat B;
2634 
2635   PetscFunctionBegin;
2636   if (scall == MAT_INITIAL_MATRIX) {
2637     PetscCall(MatCreate(subComm, &B));
2638     PetscCall(MatSetSizes(B, mat->rmap->n, mat->cmap->n, mat->rmap->n, mat->cmap->n));
2639     PetscCall(MatSetBlockSizesFromMats(B, mat, mat));
2640     PetscCall(MatSetType(B, MATSEQAIJ));
2641     PetscCall(MatDuplicateNoCreate_SeqAIJ(B, mat, MAT_COPY_VALUES, PETSC_TRUE));
2642     *subMat = B;
2643   } else {
2644     PetscCall(MatCopy_SeqAIJ(mat, *subMat, SAME_NONZERO_PATTERN));
2645   }
2646   PetscFunctionReturn(0);
2647 }
2648 
2649 PetscErrorCode MatILUFactor_SeqAIJ(Mat inA, IS row, IS col, const MatFactorInfo *info)
2650 {
2651   Mat_SeqAIJ *a = (Mat_SeqAIJ *)inA->data;
2652   Mat         outA;
2653   PetscBool   row_identity, col_identity;
2654 
2655   PetscFunctionBegin;
2656   PetscCheck(info->levels == 0, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only levels=0 supported for in-place ilu");
2657 
2658   PetscCall(ISIdentity(row, &row_identity));
2659   PetscCall(ISIdentity(col, &col_identity));
2660 
2661   outA             = inA;
2662   outA->factortype = MAT_FACTOR_LU;
2663   PetscCall(PetscFree(inA->solvertype));
2664   PetscCall(PetscStrallocpy(MATSOLVERPETSC, &inA->solvertype));
2665 
2666   PetscCall(PetscObjectReference((PetscObject)row));
2667   PetscCall(ISDestroy(&a->row));
2668 
2669   a->row = row;
2670 
2671   PetscCall(PetscObjectReference((PetscObject)col));
2672   PetscCall(ISDestroy(&a->col));
2673 
2674   a->col = col;
2675 
2676   /* Create the inverse permutation so that it can be used in MatLUFactorNumeric() */
2677   PetscCall(ISDestroy(&a->icol));
2678   PetscCall(ISInvertPermutation(col, PETSC_DECIDE, &a->icol));
2679 
2680   if (!a->solve_work) { /* this matrix may have been factored before */
2681     PetscCall(PetscMalloc1(inA->rmap->n + 1, &a->solve_work));
2682   }
2683 
2684   PetscCall(MatMarkDiagonal_SeqAIJ(inA));
2685   if (row_identity && col_identity) {
2686     PetscCall(MatLUFactorNumeric_SeqAIJ_inplace(outA, inA, info));
2687   } else {
2688     PetscCall(MatLUFactorNumeric_SeqAIJ_InplaceWithPerm(outA, inA, info));
2689   }
2690   PetscFunctionReturn(0);
2691 }
2692 
2693 PetscErrorCode MatScale_SeqAIJ(Mat inA, PetscScalar alpha)
2694 {
2695   Mat_SeqAIJ  *a = (Mat_SeqAIJ *)inA->data;
2696   PetscScalar *v;
2697   PetscBLASInt one = 1, bnz;
2698 
2699   PetscFunctionBegin;
2700   PetscCall(MatSeqAIJGetArray(inA, &v));
2701   PetscCall(PetscBLASIntCast(a->nz, &bnz));
2702   PetscCallBLAS("BLASscal", BLASscal_(&bnz, &alpha, v, &one));
2703   PetscCall(PetscLogFlops(a->nz));
2704   PetscCall(MatSeqAIJRestoreArray(inA, &v));
2705   PetscCall(MatSeqAIJInvalidateDiagonal(inA));
2706   PetscFunctionReturn(0);
2707 }
2708 
2709 PetscErrorCode MatDestroySubMatrix_Private(Mat_SubSppt *submatj)
2710 {
2711   PetscInt i;
2712 
2713   PetscFunctionBegin;
2714   if (!submatj->id) { /* delete data that are linked only to submats[id=0] */
2715     PetscCall(PetscFree4(submatj->sbuf1, submatj->ptr, submatj->tmp, submatj->ctr));
2716 
2717     for (i = 0; i < submatj->nrqr; ++i) PetscCall(PetscFree(submatj->sbuf2[i]));
2718     PetscCall(PetscFree3(submatj->sbuf2, submatj->req_size, submatj->req_source1));
2719 
2720     if (submatj->rbuf1) {
2721       PetscCall(PetscFree(submatj->rbuf1[0]));
2722       PetscCall(PetscFree(submatj->rbuf1));
2723     }
2724 
2725     for (i = 0; i < submatj->nrqs; ++i) PetscCall(PetscFree(submatj->rbuf3[i]));
2726     PetscCall(PetscFree3(submatj->req_source2, submatj->rbuf2, submatj->rbuf3));
2727     PetscCall(PetscFree(submatj->pa));
2728   }
2729 
2730 #if defined(PETSC_USE_CTABLE)
2731   PetscCall(PetscTableDestroy((PetscTable *)&submatj->rmap));
2732   if (submatj->cmap_loc) PetscCall(PetscFree(submatj->cmap_loc));
2733   PetscCall(PetscFree(submatj->rmap_loc));
2734 #else
2735   PetscCall(PetscFree(submatj->rmap));
2736 #endif
2737 
2738   if (!submatj->allcolumns) {
2739 #if defined(PETSC_USE_CTABLE)
2740     PetscCall(PetscTableDestroy((PetscTable *)&submatj->cmap));
2741 #else
2742     PetscCall(PetscFree(submatj->cmap));
2743 #endif
2744   }
2745   PetscCall(PetscFree(submatj->row2proc));
2746 
2747   PetscCall(PetscFree(submatj));
2748   PetscFunctionReturn(0);
2749 }
2750 
2751 PetscErrorCode MatDestroySubMatrix_SeqAIJ(Mat C)
2752 {
2753   Mat_SeqAIJ  *c       = (Mat_SeqAIJ *)C->data;
2754   Mat_SubSppt *submatj = c->submatis1;
2755 
2756   PetscFunctionBegin;
2757   PetscCall((*submatj->destroy)(C));
2758   PetscCall(MatDestroySubMatrix_Private(submatj));
2759   PetscFunctionReturn(0);
2760 }
2761 
2762 /* Note this has code duplication with MatDestroySubMatrices_SeqBAIJ() */
2763 PetscErrorCode MatDestroySubMatrices_SeqAIJ(PetscInt n, Mat *mat[])
2764 {
2765   PetscInt     i;
2766   Mat          C;
2767   Mat_SeqAIJ  *c;
2768   Mat_SubSppt *submatj;
2769 
2770   PetscFunctionBegin;
2771   for (i = 0; i < n; i++) {
2772     C       = (*mat)[i];
2773     c       = (Mat_SeqAIJ *)C->data;
2774     submatj = c->submatis1;
2775     if (submatj) {
2776       if (--((PetscObject)C)->refct <= 0) {
2777         PetscCall(PetscFree(C->factorprefix));
2778         PetscCall((*submatj->destroy)(C));
2779         PetscCall(MatDestroySubMatrix_Private(submatj));
2780         PetscCall(PetscFree(C->defaultvectype));
2781         PetscCall(PetscFree(C->defaultrandtype));
2782         PetscCall(PetscLayoutDestroy(&C->rmap));
2783         PetscCall(PetscLayoutDestroy(&C->cmap));
2784         PetscCall(PetscHeaderDestroy(&C));
2785       }
2786     } else {
2787       PetscCall(MatDestroy(&C));
2788     }
2789   }
2790 
2791   /* Destroy Dummy submatrices created for reuse */
2792   PetscCall(MatDestroySubMatrices_Dummy(n, mat));
2793 
2794   PetscCall(PetscFree(*mat));
2795   PetscFunctionReturn(0);
2796 }
2797 
2798 PetscErrorCode MatCreateSubMatrices_SeqAIJ(Mat A, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *B[])
2799 {
2800   PetscInt i;
2801 
2802   PetscFunctionBegin;
2803   if (scall == MAT_INITIAL_MATRIX) PetscCall(PetscCalloc1(n + 1, B));
2804 
2805   for (i = 0; i < n; i++) PetscCall(MatCreateSubMatrix_SeqAIJ(A, irow[i], icol[i], PETSC_DECIDE, scall, &(*B)[i]));
2806   PetscFunctionReturn(0);
2807 }
2808 
2809 PetscErrorCode MatIncreaseOverlap_SeqAIJ(Mat A, PetscInt is_max, IS is[], PetscInt ov)
2810 {
2811   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
2812   PetscInt        row, i, j, k, l, m, n, *nidx, isz, val;
2813   const PetscInt *idx;
2814   PetscInt        start, end, *ai, *aj;
2815   PetscBT         table;
2816 
2817   PetscFunctionBegin;
2818   m  = A->rmap->n;
2819   ai = a->i;
2820   aj = a->j;
2821 
2822   PetscCheck(ov >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "illegal negative overlap value used");
2823 
2824   PetscCall(PetscMalloc1(m + 1, &nidx));
2825   PetscCall(PetscBTCreate(m, &table));
2826 
2827   for (i = 0; i < is_max; i++) {
2828     /* Initialize the two local arrays */
2829     isz = 0;
2830     PetscCall(PetscBTMemzero(m, table));
2831 
2832     /* Extract the indices, assume there can be duplicate entries */
2833     PetscCall(ISGetIndices(is[i], &idx));
2834     PetscCall(ISGetLocalSize(is[i], &n));
2835 
2836     /* Enter these into the temp arrays. I.e., mark table[row], enter row into new index */
2837     for (j = 0; j < n; ++j) {
2838       if (!PetscBTLookupSet(table, idx[j])) nidx[isz++] = idx[j];
2839     }
2840     PetscCall(ISRestoreIndices(is[i], &idx));
2841     PetscCall(ISDestroy(&is[i]));
2842 
2843     k = 0;
2844     for (j = 0; j < ov; j++) { /* for each overlap */
2845       n = isz;
2846       for (; k < n; k++) { /* do only those rows in nidx[k], which are not done yet */
2847         row   = nidx[k];
2848         start = ai[row];
2849         end   = ai[row + 1];
2850         for (l = start; l < end; l++) {
2851           val = aj[l];
2852           if (!PetscBTLookupSet(table, val)) nidx[isz++] = val;
2853         }
2854       }
2855     }
2856     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, isz, nidx, PETSC_COPY_VALUES, (is + i)));
2857   }
2858   PetscCall(PetscBTDestroy(&table));
2859   PetscCall(PetscFree(nidx));
2860   PetscFunctionReturn(0);
2861 }
2862 
2863 /* -------------------------------------------------------------- */
2864 PetscErrorCode MatPermute_SeqAIJ(Mat A, IS rowp, IS colp, Mat *B)
2865 {
2866   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
2867   PetscInt        i, nz = 0, m = A->rmap->n, n = A->cmap->n;
2868   const PetscInt *row, *col;
2869   PetscInt       *cnew, j, *lens;
2870   IS              icolp, irowp;
2871   PetscInt       *cwork = NULL;
2872   PetscScalar    *vwork = NULL;
2873 
2874   PetscFunctionBegin;
2875   PetscCall(ISInvertPermutation(rowp, PETSC_DECIDE, &irowp));
2876   PetscCall(ISGetIndices(irowp, &row));
2877   PetscCall(ISInvertPermutation(colp, PETSC_DECIDE, &icolp));
2878   PetscCall(ISGetIndices(icolp, &col));
2879 
2880   /* determine lengths of permuted rows */
2881   PetscCall(PetscMalloc1(m + 1, &lens));
2882   for (i = 0; i < m; i++) lens[row[i]] = a->i[i + 1] - a->i[i];
2883   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
2884   PetscCall(MatSetSizes(*B, m, n, m, n));
2885   PetscCall(MatSetBlockSizesFromMats(*B, A, A));
2886   PetscCall(MatSetType(*B, ((PetscObject)A)->type_name));
2887   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*B, 0, lens));
2888   PetscCall(PetscFree(lens));
2889 
2890   PetscCall(PetscMalloc1(n, &cnew));
2891   for (i = 0; i < m; i++) {
2892     PetscCall(MatGetRow_SeqAIJ(A, i, &nz, &cwork, &vwork));
2893     for (j = 0; j < nz; j++) cnew[j] = col[cwork[j]];
2894     PetscCall(MatSetValues_SeqAIJ(*B, 1, &row[i], nz, cnew, vwork, INSERT_VALUES));
2895     PetscCall(MatRestoreRow_SeqAIJ(A, i, &nz, &cwork, &vwork));
2896   }
2897   PetscCall(PetscFree(cnew));
2898 
2899   (*B)->assembled = PETSC_FALSE;
2900 
2901 #if defined(PETSC_HAVE_DEVICE)
2902   PetscCall(MatBindToCPU(*B, A->boundtocpu));
2903 #endif
2904   PetscCall(MatAssemblyBegin(*B, MAT_FINAL_ASSEMBLY));
2905   PetscCall(MatAssemblyEnd(*B, MAT_FINAL_ASSEMBLY));
2906   PetscCall(ISRestoreIndices(irowp, &row));
2907   PetscCall(ISRestoreIndices(icolp, &col));
2908   PetscCall(ISDestroy(&irowp));
2909   PetscCall(ISDestroy(&icolp));
2910   if (rowp == colp) PetscCall(MatPropagateSymmetryOptions(A, *B));
2911   PetscFunctionReturn(0);
2912 }
2913 
2914 PetscErrorCode MatCopy_SeqAIJ(Mat A, Mat B, MatStructure str)
2915 {
2916   PetscFunctionBegin;
2917   /* If the two matrices have the same copy implementation, use fast copy. */
2918   if (str == SAME_NONZERO_PATTERN && (A->ops->copy == B->ops->copy)) {
2919     Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2920     Mat_SeqAIJ        *b = (Mat_SeqAIJ *)B->data;
2921     const PetscScalar *aa;
2922 
2923     PetscCall(MatSeqAIJGetArrayRead(A, &aa));
2924     PetscCheck(a->i[A->rmap->n] == b->i[B->rmap->n], PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Number of nonzeros in two matrices are different %" PetscInt_FMT " != %" PetscInt_FMT, a->i[A->rmap->n], b->i[B->rmap->n]);
2925     PetscCall(PetscArraycpy(b->a, aa, a->i[A->rmap->n]));
2926     PetscCall(PetscObjectStateIncrease((PetscObject)B));
2927     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2928   } else {
2929     PetscCall(MatCopy_Basic(A, B, str));
2930   }
2931   PetscFunctionReturn(0);
2932 }
2933 
2934 PetscErrorCode MatSetUp_SeqAIJ(Mat A)
2935 {
2936   PetscFunctionBegin;
2937   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(A, PETSC_DEFAULT, NULL));
2938   PetscFunctionReturn(0);
2939 }
2940 
2941 PETSC_INTERN PetscErrorCode MatSeqAIJGetArray_SeqAIJ(Mat A, PetscScalar *array[])
2942 {
2943   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
2944 
2945   PetscFunctionBegin;
2946   *array = a->a;
2947   PetscFunctionReturn(0);
2948 }
2949 
2950 PETSC_INTERN PetscErrorCode MatSeqAIJRestoreArray_SeqAIJ(Mat A, PetscScalar *array[])
2951 {
2952   PetscFunctionBegin;
2953   *array = NULL;
2954   PetscFunctionReturn(0);
2955 }
2956 
2957 /*
2958    Computes the number of nonzeros per row needed for preallocation when X and Y
2959    have different nonzero structure.
2960 */
2961 PetscErrorCode MatAXPYGetPreallocation_SeqX_private(PetscInt m, const PetscInt *xi, const PetscInt *xj, const PetscInt *yi, const PetscInt *yj, PetscInt *nnz)
2962 {
2963   PetscInt i, j, k, nzx, nzy;
2964 
2965   PetscFunctionBegin;
2966   /* Set the number of nonzeros in the new matrix */
2967   for (i = 0; i < m; i++) {
2968     const PetscInt *xjj = xj + xi[i], *yjj = yj + yi[i];
2969     nzx    = xi[i + 1] - xi[i];
2970     nzy    = yi[i + 1] - yi[i];
2971     nnz[i] = 0;
2972     for (j = 0, k = 0; j < nzx; j++) {                  /* Point in X */
2973       for (; k < nzy && yjj[k] < xjj[j]; k++) nnz[i]++; /* Catch up to X */
2974       if (k < nzy && yjj[k] == xjj[j]) k++;             /* Skip duplicate */
2975       nnz[i]++;
2976     }
2977     for (; k < nzy; k++) nnz[i]++;
2978   }
2979   PetscFunctionReturn(0);
2980 }
2981 
2982 PetscErrorCode MatAXPYGetPreallocation_SeqAIJ(Mat Y, Mat X, PetscInt *nnz)
2983 {
2984   PetscInt    m = Y->rmap->N;
2985   Mat_SeqAIJ *x = (Mat_SeqAIJ *)X->data;
2986   Mat_SeqAIJ *y = (Mat_SeqAIJ *)Y->data;
2987 
2988   PetscFunctionBegin;
2989   /* Set the number of nonzeros in the new matrix */
2990   PetscCall(MatAXPYGetPreallocation_SeqX_private(m, x->i, x->j, y->i, y->j, nnz));
2991   PetscFunctionReturn(0);
2992 }
2993 
2994 PetscErrorCode MatAXPY_SeqAIJ(Mat Y, PetscScalar a, Mat X, MatStructure str)
2995 {
2996   Mat_SeqAIJ *x = (Mat_SeqAIJ *)X->data, *y = (Mat_SeqAIJ *)Y->data;
2997 
2998   PetscFunctionBegin;
2999   if (str == UNKNOWN_NONZERO_PATTERN || (PetscDefined(USE_DEBUG) && str == SAME_NONZERO_PATTERN)) {
3000     PetscBool e = x->nz == y->nz ? PETSC_TRUE : PETSC_FALSE;
3001     if (e) {
3002       PetscCall(PetscArraycmp(x->i, y->i, Y->rmap->n + 1, &e));
3003       if (e) {
3004         PetscCall(PetscArraycmp(x->j, y->j, y->nz, &e));
3005         if (e) str = SAME_NONZERO_PATTERN;
3006       }
3007     }
3008     if (!e) PetscCheck(str != SAME_NONZERO_PATTERN, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "MatStructure is not SAME_NONZERO_PATTERN");
3009   }
3010   if (str == SAME_NONZERO_PATTERN) {
3011     const PetscScalar *xa;
3012     PetscScalar       *ya, alpha = a;
3013     PetscBLASInt       one = 1, bnz;
3014 
3015     PetscCall(PetscBLASIntCast(x->nz, &bnz));
3016     PetscCall(MatSeqAIJGetArray(Y, &ya));
3017     PetscCall(MatSeqAIJGetArrayRead(X, &xa));
3018     PetscCallBLAS("BLASaxpy", BLASaxpy_(&bnz, &alpha, xa, &one, ya, &one));
3019     PetscCall(MatSeqAIJRestoreArrayRead(X, &xa));
3020     PetscCall(MatSeqAIJRestoreArray(Y, &ya));
3021     PetscCall(PetscLogFlops(2.0 * bnz));
3022     PetscCall(MatSeqAIJInvalidateDiagonal(Y));
3023     PetscCall(PetscObjectStateIncrease((PetscObject)Y));
3024   } else if (str == SUBSET_NONZERO_PATTERN) { /* nonzeros of X is a subset of Y's */
3025     PetscCall(MatAXPY_Basic(Y, a, X, str));
3026   } else {
3027     Mat       B;
3028     PetscInt *nnz;
3029     PetscCall(PetscMalloc1(Y->rmap->N, &nnz));
3030     PetscCall(MatCreate(PetscObjectComm((PetscObject)Y), &B));
3031     PetscCall(PetscObjectSetName((PetscObject)B, ((PetscObject)Y)->name));
3032     PetscCall(MatSetLayouts(B, Y->rmap, Y->cmap));
3033     PetscCall(MatSetType(B, ((PetscObject)Y)->type_name));
3034     PetscCall(MatAXPYGetPreallocation_SeqAIJ(Y, X, nnz));
3035     PetscCall(MatSeqAIJSetPreallocation(B, 0, nnz));
3036     PetscCall(MatAXPY_BasicWithPreallocation(B, Y, a, X, str));
3037     PetscCall(MatHeaderMerge(Y, &B));
3038     PetscCall(MatSeqAIJCheckInode(Y));
3039     PetscCall(PetscFree(nnz));
3040   }
3041   PetscFunctionReturn(0);
3042 }
3043 
3044 PETSC_INTERN PetscErrorCode MatConjugate_SeqAIJ(Mat mat)
3045 {
3046 #if defined(PETSC_USE_COMPLEX)
3047   Mat_SeqAIJ  *aij = (Mat_SeqAIJ *)mat->data;
3048   PetscInt     i, nz;
3049   PetscScalar *a;
3050 
3051   PetscFunctionBegin;
3052   nz = aij->nz;
3053   PetscCall(MatSeqAIJGetArray(mat, &a));
3054   for (i = 0; i < nz; i++) a[i] = PetscConj(a[i]);
3055   PetscCall(MatSeqAIJRestoreArray(mat, &a));
3056 #else
3057   PetscFunctionBegin;
3058 #endif
3059   PetscFunctionReturn(0);
3060 }
3061 
3062 PetscErrorCode MatGetRowMaxAbs_SeqAIJ(Mat A, Vec v, PetscInt idx[])
3063 {
3064   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3065   PetscInt         i, j, m = A->rmap->n, *ai, *aj, ncols, n;
3066   PetscReal        atmp;
3067   PetscScalar     *x;
3068   const MatScalar *aa, *av;
3069 
3070   PetscFunctionBegin;
3071   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3072   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3073   aa = av;
3074   ai = a->i;
3075   aj = a->j;
3076 
3077   PetscCall(VecSet(v, 0.0));
3078   PetscCall(VecGetArrayWrite(v, &x));
3079   PetscCall(VecGetLocalSize(v, &n));
3080   PetscCheck(n == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
3081   for (i = 0; i < m; i++) {
3082     ncols = ai[1] - ai[0];
3083     ai++;
3084     for (j = 0; j < ncols; j++) {
3085       atmp = PetscAbsScalar(*aa);
3086       if (PetscAbsScalar(x[i]) < atmp) {
3087         x[i] = atmp;
3088         if (idx) idx[i] = *aj;
3089       }
3090       aa++;
3091       aj++;
3092     }
3093   }
3094   PetscCall(VecRestoreArrayWrite(v, &x));
3095   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3096   PetscFunctionReturn(0);
3097 }
3098 
3099 PetscErrorCode MatGetRowMax_SeqAIJ(Mat A, Vec v, PetscInt idx[])
3100 {
3101   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3102   PetscInt         i, j, m = A->rmap->n, *ai, *aj, ncols, n;
3103   PetscScalar     *x;
3104   const MatScalar *aa, *av;
3105 
3106   PetscFunctionBegin;
3107   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3108   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3109   aa = av;
3110   ai = a->i;
3111   aj = a->j;
3112 
3113   PetscCall(VecSet(v, 0.0));
3114   PetscCall(VecGetArrayWrite(v, &x));
3115   PetscCall(VecGetLocalSize(v, &n));
3116   PetscCheck(n == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
3117   for (i = 0; i < m; i++) {
3118     ncols = ai[1] - ai[0];
3119     ai++;
3120     if (ncols == A->cmap->n) { /* row is dense */
3121       x[i] = *aa;
3122       if (idx) idx[i] = 0;
3123     } else { /* row is sparse so already KNOW maximum is 0.0 or higher */
3124       x[i] = 0.0;
3125       if (idx) {
3126         for (j = 0; j < ncols; j++) { /* find first implicit 0.0 in the row */
3127           if (aj[j] > j) {
3128             idx[i] = j;
3129             break;
3130           }
3131         }
3132         /* in case first implicit 0.0 in the row occurs at ncols-th column */
3133         if (j == ncols && j < A->cmap->n) idx[i] = j;
3134       }
3135     }
3136     for (j = 0; j < ncols; j++) {
3137       if (PetscRealPart(x[i]) < PetscRealPart(*aa)) {
3138         x[i] = *aa;
3139         if (idx) idx[i] = *aj;
3140       }
3141       aa++;
3142       aj++;
3143     }
3144   }
3145   PetscCall(VecRestoreArrayWrite(v, &x));
3146   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3147   PetscFunctionReturn(0);
3148 }
3149 
3150 PetscErrorCode MatGetRowMinAbs_SeqAIJ(Mat A, Vec v, PetscInt idx[])
3151 {
3152   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3153   PetscInt         i, j, m = A->rmap->n, *ai, *aj, ncols, n;
3154   PetscScalar     *x;
3155   const MatScalar *aa, *av;
3156 
3157   PetscFunctionBegin;
3158   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3159   aa = av;
3160   ai = a->i;
3161   aj = a->j;
3162 
3163   PetscCall(VecSet(v, 0.0));
3164   PetscCall(VecGetArrayWrite(v, &x));
3165   PetscCall(VecGetLocalSize(v, &n));
3166   PetscCheck(n == m, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector, %" PetscInt_FMT " vs. %" PetscInt_FMT " rows", m, n);
3167   for (i = 0; i < m; i++) {
3168     ncols = ai[1] - ai[0];
3169     ai++;
3170     if (ncols == A->cmap->n) { /* row is dense */
3171       x[i] = *aa;
3172       if (idx) idx[i] = 0;
3173     } else { /* row is sparse so already KNOW minimum is 0.0 or higher */
3174       x[i] = 0.0;
3175       if (idx) { /* find first implicit 0.0 in the row */
3176         for (j = 0; j < ncols; j++) {
3177           if (aj[j] > j) {
3178             idx[i] = j;
3179             break;
3180           }
3181         }
3182         /* in case first implicit 0.0 in the row occurs at ncols-th column */
3183         if (j == ncols && j < A->cmap->n) idx[i] = j;
3184       }
3185     }
3186     for (j = 0; j < ncols; j++) {
3187       if (PetscAbsScalar(x[i]) > PetscAbsScalar(*aa)) {
3188         x[i] = *aa;
3189         if (idx) idx[i] = *aj;
3190       }
3191       aa++;
3192       aj++;
3193     }
3194   }
3195   PetscCall(VecRestoreArrayWrite(v, &x));
3196   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3197   PetscFunctionReturn(0);
3198 }
3199 
3200 PetscErrorCode MatGetRowMin_SeqAIJ(Mat A, Vec v, PetscInt idx[])
3201 {
3202   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3203   PetscInt         i, j, m = A->rmap->n, ncols, n;
3204   const PetscInt  *ai, *aj;
3205   PetscScalar     *x;
3206   const MatScalar *aa, *av;
3207 
3208   PetscFunctionBegin;
3209   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3210   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3211   aa = av;
3212   ai = a->i;
3213   aj = a->j;
3214 
3215   PetscCall(VecSet(v, 0.0));
3216   PetscCall(VecGetArrayWrite(v, &x));
3217   PetscCall(VecGetLocalSize(v, &n));
3218   PetscCheck(n == m, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
3219   for (i = 0; i < m; i++) {
3220     ncols = ai[1] - ai[0];
3221     ai++;
3222     if (ncols == A->cmap->n) { /* row is dense */
3223       x[i] = *aa;
3224       if (idx) idx[i] = 0;
3225     } else { /* row is sparse so already KNOW minimum is 0.0 or lower */
3226       x[i] = 0.0;
3227       if (idx) { /* find first implicit 0.0 in the row */
3228         for (j = 0; j < ncols; j++) {
3229           if (aj[j] > j) {
3230             idx[i] = j;
3231             break;
3232           }
3233         }
3234         /* in case first implicit 0.0 in the row occurs at ncols-th column */
3235         if (j == ncols && j < A->cmap->n) idx[i] = j;
3236       }
3237     }
3238     for (j = 0; j < ncols; j++) {
3239       if (PetscRealPart(x[i]) > PetscRealPart(*aa)) {
3240         x[i] = *aa;
3241         if (idx) idx[i] = *aj;
3242       }
3243       aa++;
3244       aj++;
3245     }
3246   }
3247   PetscCall(VecRestoreArrayWrite(v, &x));
3248   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3249   PetscFunctionReturn(0);
3250 }
3251 
3252 PetscErrorCode MatInvertBlockDiagonal_SeqAIJ(Mat A, const PetscScalar **values)
3253 {
3254   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
3255   PetscInt        i, bs = PetscAbs(A->rmap->bs), mbs = A->rmap->n / bs, ipvt[5], bs2 = bs * bs, *v_pivots, ij[7], *IJ, j;
3256   MatScalar      *diag, work[25], *v_work;
3257   const PetscReal shift = 0.0;
3258   PetscBool       allowzeropivot, zeropivotdetected = PETSC_FALSE;
3259 
3260   PetscFunctionBegin;
3261   allowzeropivot = PetscNot(A->erroriffailure);
3262   if (a->ibdiagvalid) {
3263     if (values) *values = a->ibdiag;
3264     PetscFunctionReturn(0);
3265   }
3266   PetscCall(MatMarkDiagonal_SeqAIJ(A));
3267   if (!a->ibdiag) { PetscCall(PetscMalloc1(bs2 * mbs, &a->ibdiag)); }
3268   diag = a->ibdiag;
3269   if (values) *values = a->ibdiag;
3270   /* factor and invert each block */
3271   switch (bs) {
3272   case 1:
3273     for (i = 0; i < mbs; i++) {
3274       PetscCall(MatGetValues(A, 1, &i, 1, &i, diag + i));
3275       if (PetscAbsScalar(diag[i] + shift) < PETSC_MACHINE_EPSILON) {
3276         if (allowzeropivot) {
3277           A->factorerrortype             = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3278           A->factorerror_zeropivot_value = PetscAbsScalar(diag[i]);
3279           A->factorerror_zeropivot_row   = i;
3280           PetscCall(PetscInfo(A, "Zero pivot, row %" PetscInt_FMT " pivot %g tolerance %g\n", i, (double)PetscAbsScalar(diag[i]), (double)PETSC_MACHINE_EPSILON));
3281         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_MAT_LU_ZRPVT, "Zero pivot, row %" PetscInt_FMT " pivot %g tolerance %g", i, (double)PetscAbsScalar(diag[i]), (double)PETSC_MACHINE_EPSILON);
3282       }
3283       diag[i] = (PetscScalar)1.0 / (diag[i] + shift);
3284     }
3285     break;
3286   case 2:
3287     for (i = 0; i < mbs; i++) {
3288       ij[0] = 2 * i;
3289       ij[1] = 2 * i + 1;
3290       PetscCall(MatGetValues(A, 2, ij, 2, ij, diag));
3291       PetscCall(PetscKernel_A_gets_inverse_A_2(diag, shift, allowzeropivot, &zeropivotdetected));
3292       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3293       PetscCall(PetscKernel_A_gets_transpose_A_2(diag));
3294       diag += 4;
3295     }
3296     break;
3297   case 3:
3298     for (i = 0; i < mbs; i++) {
3299       ij[0] = 3 * i;
3300       ij[1] = 3 * i + 1;
3301       ij[2] = 3 * i + 2;
3302       PetscCall(MatGetValues(A, 3, ij, 3, ij, diag));
3303       PetscCall(PetscKernel_A_gets_inverse_A_3(diag, shift, allowzeropivot, &zeropivotdetected));
3304       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3305       PetscCall(PetscKernel_A_gets_transpose_A_3(diag));
3306       diag += 9;
3307     }
3308     break;
3309   case 4:
3310     for (i = 0; i < mbs; i++) {
3311       ij[0] = 4 * i;
3312       ij[1] = 4 * i + 1;
3313       ij[2] = 4 * i + 2;
3314       ij[3] = 4 * i + 3;
3315       PetscCall(MatGetValues(A, 4, ij, 4, ij, diag));
3316       PetscCall(PetscKernel_A_gets_inverse_A_4(diag, shift, allowzeropivot, &zeropivotdetected));
3317       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3318       PetscCall(PetscKernel_A_gets_transpose_A_4(diag));
3319       diag += 16;
3320     }
3321     break;
3322   case 5:
3323     for (i = 0; i < mbs; i++) {
3324       ij[0] = 5 * i;
3325       ij[1] = 5 * i + 1;
3326       ij[2] = 5 * i + 2;
3327       ij[3] = 5 * i + 3;
3328       ij[4] = 5 * i + 4;
3329       PetscCall(MatGetValues(A, 5, ij, 5, ij, diag));
3330       PetscCall(PetscKernel_A_gets_inverse_A_5(diag, ipvt, work, shift, allowzeropivot, &zeropivotdetected));
3331       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3332       PetscCall(PetscKernel_A_gets_transpose_A_5(diag));
3333       diag += 25;
3334     }
3335     break;
3336   case 6:
3337     for (i = 0; i < mbs; i++) {
3338       ij[0] = 6 * i;
3339       ij[1] = 6 * i + 1;
3340       ij[2] = 6 * i + 2;
3341       ij[3] = 6 * i + 3;
3342       ij[4] = 6 * i + 4;
3343       ij[5] = 6 * i + 5;
3344       PetscCall(MatGetValues(A, 6, ij, 6, ij, diag));
3345       PetscCall(PetscKernel_A_gets_inverse_A_6(diag, shift, allowzeropivot, &zeropivotdetected));
3346       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3347       PetscCall(PetscKernel_A_gets_transpose_A_6(diag));
3348       diag += 36;
3349     }
3350     break;
3351   case 7:
3352     for (i = 0; i < mbs; i++) {
3353       ij[0] = 7 * i;
3354       ij[1] = 7 * i + 1;
3355       ij[2] = 7 * i + 2;
3356       ij[3] = 7 * i + 3;
3357       ij[4] = 7 * i + 4;
3358       ij[5] = 7 * i + 5;
3359       ij[5] = 7 * i + 6;
3360       PetscCall(MatGetValues(A, 7, ij, 7, ij, diag));
3361       PetscCall(PetscKernel_A_gets_inverse_A_7(diag, shift, allowzeropivot, &zeropivotdetected));
3362       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3363       PetscCall(PetscKernel_A_gets_transpose_A_7(diag));
3364       diag += 49;
3365     }
3366     break;
3367   default:
3368     PetscCall(PetscMalloc3(bs, &v_work, bs, &v_pivots, bs, &IJ));
3369     for (i = 0; i < mbs; i++) {
3370       for (j = 0; j < bs; j++) IJ[j] = bs * i + j;
3371       PetscCall(MatGetValues(A, bs, IJ, bs, IJ, diag));
3372       PetscCall(PetscKernel_A_gets_inverse_A(bs, diag, v_pivots, v_work, allowzeropivot, &zeropivotdetected));
3373       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3374       PetscCall(PetscKernel_A_gets_transpose_A_N(diag, bs));
3375       diag += bs2;
3376     }
3377     PetscCall(PetscFree3(v_work, v_pivots, IJ));
3378   }
3379   a->ibdiagvalid = PETSC_TRUE;
3380   PetscFunctionReturn(0);
3381 }
3382 
3383 static PetscErrorCode MatSetRandom_SeqAIJ(Mat x, PetscRandom rctx)
3384 {
3385   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)x->data;
3386   PetscScalar a, *aa;
3387   PetscInt    m, n, i, j, col;
3388 
3389   PetscFunctionBegin;
3390   if (!x->assembled) {
3391     PetscCall(MatGetSize(x, &m, &n));
3392     for (i = 0; i < m; i++) {
3393       for (j = 0; j < aij->imax[i]; j++) {
3394         PetscCall(PetscRandomGetValue(rctx, &a));
3395         col = (PetscInt)(n * PetscRealPart(a));
3396         PetscCall(MatSetValues(x, 1, &i, 1, &col, &a, ADD_VALUES));
3397       }
3398     }
3399   } else {
3400     PetscCall(MatSeqAIJGetArrayWrite(x, &aa));
3401     for (i = 0; i < aij->nz; i++) PetscCall(PetscRandomGetValue(rctx, aa + i));
3402     PetscCall(MatSeqAIJRestoreArrayWrite(x, &aa));
3403   }
3404   PetscCall(MatAssemblyBegin(x, MAT_FINAL_ASSEMBLY));
3405   PetscCall(MatAssemblyEnd(x, MAT_FINAL_ASSEMBLY));
3406   PetscFunctionReturn(0);
3407 }
3408 
3409 /* Like MatSetRandom_SeqAIJ, but do not set values on columns in range of [low, high) */
3410 PetscErrorCode MatSetRandomSkipColumnRange_SeqAIJ_Private(Mat x, PetscInt low, PetscInt high, PetscRandom rctx)
3411 {
3412   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)x->data;
3413   PetscScalar a;
3414   PetscInt    m, n, i, j, col, nskip;
3415 
3416   PetscFunctionBegin;
3417   nskip = high - low;
3418   PetscCall(MatGetSize(x, &m, &n));
3419   n -= nskip; /* shrink number of columns where nonzeros can be set */
3420   for (i = 0; i < m; i++) {
3421     for (j = 0; j < aij->imax[i]; j++) {
3422       PetscCall(PetscRandomGetValue(rctx, &a));
3423       col = (PetscInt)(n * PetscRealPart(a));
3424       if (col >= low) col += nskip; /* shift col rightward to skip the hole */
3425       PetscCall(MatSetValues(x, 1, &i, 1, &col, &a, ADD_VALUES));
3426     }
3427   }
3428   PetscCall(MatAssemblyBegin(x, MAT_FINAL_ASSEMBLY));
3429   PetscCall(MatAssemblyEnd(x, MAT_FINAL_ASSEMBLY));
3430   PetscFunctionReturn(0);
3431 }
3432 
3433 /* -------------------------------------------------------------------*/
3434 static struct _MatOps MatOps_Values = {MatSetValues_SeqAIJ,
3435                                        MatGetRow_SeqAIJ,
3436                                        MatRestoreRow_SeqAIJ,
3437                                        MatMult_SeqAIJ,
3438                                        /*  4*/ MatMultAdd_SeqAIJ,
3439                                        MatMultTranspose_SeqAIJ,
3440                                        MatMultTransposeAdd_SeqAIJ,
3441                                        NULL,
3442                                        NULL,
3443                                        NULL,
3444                                        /* 10*/ NULL,
3445                                        MatLUFactor_SeqAIJ,
3446                                        NULL,
3447                                        MatSOR_SeqAIJ,
3448                                        MatTranspose_SeqAIJ,
3449                                        /*1 5*/ MatGetInfo_SeqAIJ,
3450                                        MatEqual_SeqAIJ,
3451                                        MatGetDiagonal_SeqAIJ,
3452                                        MatDiagonalScale_SeqAIJ,
3453                                        MatNorm_SeqAIJ,
3454                                        /* 20*/ NULL,
3455                                        MatAssemblyEnd_SeqAIJ,
3456                                        MatSetOption_SeqAIJ,
3457                                        MatZeroEntries_SeqAIJ,
3458                                        /* 24*/ MatZeroRows_SeqAIJ,
3459                                        NULL,
3460                                        NULL,
3461                                        NULL,
3462                                        NULL,
3463                                        /* 29*/ MatSetUp_SeqAIJ,
3464                                        NULL,
3465                                        NULL,
3466                                        NULL,
3467                                        NULL,
3468                                        /* 34*/ MatDuplicate_SeqAIJ,
3469                                        NULL,
3470                                        NULL,
3471                                        MatILUFactor_SeqAIJ,
3472                                        NULL,
3473                                        /* 39*/ MatAXPY_SeqAIJ,
3474                                        MatCreateSubMatrices_SeqAIJ,
3475                                        MatIncreaseOverlap_SeqAIJ,
3476                                        MatGetValues_SeqAIJ,
3477                                        MatCopy_SeqAIJ,
3478                                        /* 44*/ MatGetRowMax_SeqAIJ,
3479                                        MatScale_SeqAIJ,
3480                                        MatShift_SeqAIJ,
3481                                        MatDiagonalSet_SeqAIJ,
3482                                        MatZeroRowsColumns_SeqAIJ,
3483                                        /* 49*/ MatSetRandom_SeqAIJ,
3484                                        MatGetRowIJ_SeqAIJ,
3485                                        MatRestoreRowIJ_SeqAIJ,
3486                                        MatGetColumnIJ_SeqAIJ,
3487                                        MatRestoreColumnIJ_SeqAIJ,
3488                                        /* 54*/ MatFDColoringCreate_SeqXAIJ,
3489                                        NULL,
3490                                        NULL,
3491                                        MatPermute_SeqAIJ,
3492                                        NULL,
3493                                        /* 59*/ NULL,
3494                                        MatDestroy_SeqAIJ,
3495                                        MatView_SeqAIJ,
3496                                        NULL,
3497                                        NULL,
3498                                        /* 64*/ NULL,
3499                                        MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqAIJ,
3500                                        NULL,
3501                                        NULL,
3502                                        NULL,
3503                                        /* 69*/ MatGetRowMaxAbs_SeqAIJ,
3504                                        MatGetRowMinAbs_SeqAIJ,
3505                                        NULL,
3506                                        NULL,
3507                                        NULL,
3508                                        /* 74*/ NULL,
3509                                        MatFDColoringApply_AIJ,
3510                                        NULL,
3511                                        NULL,
3512                                        NULL,
3513                                        /* 79*/ MatFindZeroDiagonals_SeqAIJ,
3514                                        NULL,
3515                                        NULL,
3516                                        NULL,
3517                                        MatLoad_SeqAIJ,
3518                                        /* 84*/ MatIsSymmetric_SeqAIJ,
3519                                        MatIsHermitian_SeqAIJ,
3520                                        NULL,
3521                                        NULL,
3522                                        NULL,
3523                                        /* 89*/ NULL,
3524                                        NULL,
3525                                        MatMatMultNumeric_SeqAIJ_SeqAIJ,
3526                                        NULL,
3527                                        NULL,
3528                                        /* 94*/ MatPtAPNumeric_SeqAIJ_SeqAIJ_SparseAxpy,
3529                                        NULL,
3530                                        NULL,
3531                                        MatMatTransposeMultNumeric_SeqAIJ_SeqAIJ,
3532                                        NULL,
3533                                        /* 99*/ MatProductSetFromOptions_SeqAIJ,
3534                                        NULL,
3535                                        NULL,
3536                                        MatConjugate_SeqAIJ,
3537                                        NULL,
3538                                        /*104*/ MatSetValuesRow_SeqAIJ,
3539                                        MatRealPart_SeqAIJ,
3540                                        MatImaginaryPart_SeqAIJ,
3541                                        NULL,
3542                                        NULL,
3543                                        /*109*/ MatMatSolve_SeqAIJ,
3544                                        NULL,
3545                                        MatGetRowMin_SeqAIJ,
3546                                        NULL,
3547                                        MatMissingDiagonal_SeqAIJ,
3548                                        /*114*/ NULL,
3549                                        NULL,
3550                                        NULL,
3551                                        NULL,
3552                                        NULL,
3553                                        /*119*/ NULL,
3554                                        NULL,
3555                                        NULL,
3556                                        NULL,
3557                                        MatGetMultiProcBlock_SeqAIJ,
3558                                        /*124*/ MatFindNonzeroRows_SeqAIJ,
3559                                        MatGetColumnReductions_SeqAIJ,
3560                                        MatInvertBlockDiagonal_SeqAIJ,
3561                                        MatInvertVariableBlockDiagonal_SeqAIJ,
3562                                        NULL,
3563                                        /*129*/ NULL,
3564                                        NULL,
3565                                        NULL,
3566                                        MatTransposeMatMultNumeric_SeqAIJ_SeqAIJ,
3567                                        MatTransposeColoringCreate_SeqAIJ,
3568                                        /*134*/ MatTransColoringApplySpToDen_SeqAIJ,
3569                                        MatTransColoringApplyDenToSp_SeqAIJ,
3570                                        NULL,
3571                                        NULL,
3572                                        MatRARtNumeric_SeqAIJ_SeqAIJ,
3573                                        /*139*/ NULL,
3574                                        NULL,
3575                                        NULL,
3576                                        MatFDColoringSetUp_SeqXAIJ,
3577                                        MatFindOffBlockDiagonalEntries_SeqAIJ,
3578                                        MatCreateMPIMatConcatenateSeqMat_SeqAIJ,
3579                                        /*145*/ MatDestroySubMatrices_SeqAIJ,
3580                                        NULL,
3581                                        NULL,
3582                                        MatCreateGraph_Simple_AIJ,
3583                                        NULL,
3584                                        /*150*/ MatTransposeSymbolic_SeqAIJ};
3585 
3586 PetscErrorCode MatSeqAIJSetColumnIndices_SeqAIJ(Mat mat, PetscInt *indices)
3587 {
3588   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)mat->data;
3589   PetscInt    i, nz, n;
3590 
3591   PetscFunctionBegin;
3592   nz = aij->maxnz;
3593   n  = mat->rmap->n;
3594   for (i = 0; i < nz; i++) aij->j[i] = indices[i];
3595   aij->nz = nz;
3596   for (i = 0; i < n; i++) aij->ilen[i] = aij->imax[i];
3597   PetscFunctionReturn(0);
3598 }
3599 
3600 /*
3601  * Given a sparse matrix with global column indices, compact it by using a local column space.
3602  * The result matrix helps saving memory in other algorithms, such as MatPtAPSymbolic_MPIAIJ_MPIAIJ_scalable()
3603  */
3604 PetscErrorCode MatSeqAIJCompactOutExtraColumns_SeqAIJ(Mat mat, ISLocalToGlobalMapping *mapping)
3605 {
3606   Mat_SeqAIJ        *aij = (Mat_SeqAIJ *)mat->data;
3607   PetscTable         gid1_lid1;
3608   PetscTablePosition tpos;
3609   PetscInt           gid, lid, i, ec, nz = aij->nz;
3610   PetscInt          *garray, *jj = aij->j;
3611 
3612   PetscFunctionBegin;
3613   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
3614   PetscValidPointer(mapping, 2);
3615   /* use a table */
3616   PetscCall(PetscTableCreate(mat->rmap->n, mat->cmap->N + 1, &gid1_lid1));
3617   ec = 0;
3618   for (i = 0; i < nz; i++) {
3619     PetscInt data, gid1 = jj[i] + 1;
3620     PetscCall(PetscTableFind(gid1_lid1, gid1, &data));
3621     if (!data) {
3622       /* one based table */
3623       PetscCall(PetscTableAdd(gid1_lid1, gid1, ++ec, INSERT_VALUES));
3624     }
3625   }
3626   /* form array of columns we need */
3627   PetscCall(PetscMalloc1(ec, &garray));
3628   PetscCall(PetscTableGetHeadPosition(gid1_lid1, &tpos));
3629   while (tpos) {
3630     PetscCall(PetscTableGetNext(gid1_lid1, &tpos, &gid, &lid));
3631     gid--;
3632     lid--;
3633     garray[lid] = gid;
3634   }
3635   PetscCall(PetscSortInt(ec, garray)); /* sort, and rebuild */
3636   PetscCall(PetscTableRemoveAll(gid1_lid1));
3637   for (i = 0; i < ec; i++) PetscCall(PetscTableAdd(gid1_lid1, garray[i] + 1, i + 1, INSERT_VALUES));
3638   /* compact out the extra columns in B */
3639   for (i = 0; i < nz; i++) {
3640     PetscInt gid1 = jj[i] + 1;
3641     PetscCall(PetscTableFind(gid1_lid1, gid1, &lid));
3642     lid--;
3643     jj[i] = lid;
3644   }
3645   PetscCall(PetscLayoutDestroy(&mat->cmap));
3646   PetscCall(PetscTableDestroy(&gid1_lid1));
3647   PetscCall(PetscLayoutCreateFromSizes(PetscObjectComm((PetscObject)mat), ec, ec, 1, &mat->cmap));
3648   PetscCall(ISLocalToGlobalMappingCreate(PETSC_COMM_SELF, mat->cmap->bs, mat->cmap->n, garray, PETSC_OWN_POINTER, mapping));
3649   PetscCall(ISLocalToGlobalMappingSetType(*mapping, ISLOCALTOGLOBALMAPPINGHASH));
3650   PetscFunctionReturn(0);
3651 }
3652 
3653 /*@
3654     MatSeqAIJSetColumnIndices - Set the column indices for all the rows
3655        in the matrix.
3656 
3657   Input Parameters:
3658 +  mat - the `MATSEQAIJ` matrix
3659 -  indices - the column indices
3660 
3661   Level: advanced
3662 
3663   Notes:
3664     This can be called if you have precomputed the nonzero structure of the
3665   matrix and want to provide it to the matrix object to improve the performance
3666   of the `MatSetValues()` operation.
3667 
3668     You MUST have set the correct numbers of nonzeros per row in the call to
3669   `MatCreateSeqAIJ()`, and the columns indices MUST be sorted.
3670 
3671     MUST be called before any calls to `MatSetValues()`
3672 
3673     The indices should start with zero, not one.
3674 
3675 @*/
3676 PetscErrorCode MatSeqAIJSetColumnIndices(Mat mat, PetscInt *indices)
3677 {
3678   PetscFunctionBegin;
3679   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
3680   PetscValidIntPointer(indices, 2);
3681   PetscUseMethod(mat, "MatSeqAIJSetColumnIndices_C", (Mat, PetscInt *), (mat, indices));
3682   PetscFunctionReturn(0);
3683 }
3684 
3685 /* ----------------------------------------------------------------------------------------*/
3686 
3687 PetscErrorCode MatStoreValues_SeqAIJ(Mat mat)
3688 {
3689   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)mat->data;
3690   size_t      nz  = aij->i[mat->rmap->n];
3691 
3692   PetscFunctionBegin;
3693   PetscCheck(aij->nonew, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatSetOption(A,MAT_NEW_NONZERO_LOCATIONS,PETSC_FALSE);first");
3694 
3695   /* allocate space for values if not already there */
3696   if (!aij->saved_values) { PetscCall(PetscMalloc1(nz + 1, &aij->saved_values)); }
3697 
3698   /* copy values over */
3699   PetscCall(PetscArraycpy(aij->saved_values, aij->a, nz));
3700   PetscFunctionReturn(0);
3701 }
3702 
3703 /*@
3704     MatStoreValues - Stashes a copy of the matrix values; this allows, for
3705        example, reuse of the linear part of a Jacobian, while recomputing the
3706        nonlinear portion.
3707 
3708    Collect on mat
3709 
3710   Input Parameters:
3711 .  mat - the matrix (currently only `MATAIJ` matrices support this option)
3712 
3713   Level: advanced
3714 
3715   Common Usage, with `SNESSolve()`:
3716 $    Create Jacobian matrix
3717 $    Set linear terms into matrix
3718 $    Apply boundary conditions to matrix, at this time matrix must have
3719 $      final nonzero structure (i.e. setting the nonlinear terms and applying
3720 $      boundary conditions again will not change the nonzero structure
3721 $    ierr = MatSetOption(mat,MAT_NEW_NONZERO_LOCATIONS,PETSC_FALSE);
3722 $    ierr = MatStoreValues(mat);
3723 $    Call SNESSetJacobian() with matrix
3724 $    In your Jacobian routine
3725 $      ierr = MatRetrieveValues(mat);
3726 $      Set nonlinear terms in matrix
3727 
3728   Common Usage without SNESSolve(), i.e. when you handle nonlinear solve yourself:
3729 $    // build linear portion of Jacobian
3730 $    ierr = MatSetOption(mat,MAT_NEW_NONZERO_LOCATIONS,PETSC_FALSE);
3731 $    ierr = MatStoreValues(mat);
3732 $    loop over nonlinear iterations
3733 $       ierr = MatRetrieveValues(mat);
3734 $       // call MatSetValues(mat,...) to set nonliner portion of Jacobian
3735 $       // call MatAssemblyBegin/End() on matrix
3736 $       Solve linear system with Jacobian
3737 $    endloop
3738 
3739   Notes:
3740     Matrix must already be assemblied before calling this routine
3741     Must set the matrix option `MatSetOption`(mat,`MAT_NEW_NONZERO_LOCATIONS`,`PETSC_FALSE`); before
3742     calling this routine.
3743 
3744     When this is called multiple times it overwrites the previous set of stored values
3745     and does not allocated additional space.
3746 
3747 .seealso: `MatRetrieveValues()`
3748 @*/
3749 PetscErrorCode MatStoreValues(Mat mat)
3750 {
3751   PetscFunctionBegin;
3752   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
3753   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3754   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3755   PetscUseMethod(mat, "MatStoreValues_C", (Mat), (mat));
3756   PetscFunctionReturn(0);
3757 }
3758 
3759 PetscErrorCode MatRetrieveValues_SeqAIJ(Mat mat)
3760 {
3761   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)mat->data;
3762   PetscInt    nz  = aij->i[mat->rmap->n];
3763 
3764   PetscFunctionBegin;
3765   PetscCheck(aij->nonew, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatSetOption(A,MAT_NEW_NONZERO_LOCATIONS,PETSC_FALSE);first");
3766   PetscCheck(aij->saved_values, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatStoreValues(A);first");
3767   /* copy values over */
3768   PetscCall(PetscArraycpy(aij->a, aij->saved_values, nz));
3769   PetscFunctionReturn(0);
3770 }
3771 
3772 /*@
3773     MatRetrieveValues - Retrieves the copy of the matrix values; this allows, for
3774        example, reuse of the linear part of a Jacobian, while recomputing the
3775        nonlinear portion.
3776 
3777    Collect on mat
3778 
3779   Input Parameters:
3780 .  mat - the matrix (currently only `MATAIJ` matrices support this option)
3781 
3782   Level: advanced
3783 
3784 .seealso: `MatStoreValues()`
3785 @*/
3786 PetscErrorCode MatRetrieveValues(Mat mat)
3787 {
3788   PetscFunctionBegin;
3789   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
3790   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3791   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3792   PetscUseMethod(mat, "MatRetrieveValues_C", (Mat), (mat));
3793   PetscFunctionReturn(0);
3794 }
3795 
3796 /* --------------------------------------------------------------------------------*/
3797 /*@C
3798    MatCreateSeqAIJ - Creates a sparse matrix in `MATSEQAIJ` (compressed row) format
3799    (the default parallel PETSc format).  For good matrix assembly performance
3800    the user should preallocate the matrix storage by setting the parameter nz
3801    (or the array nnz).  By setting these parameters accurately, performance
3802    during matrix assembly can be increased by more than a factor of 50.
3803 
3804    Collective
3805 
3806    Input Parameters:
3807 +  comm - MPI communicator, set to `PETSC_COMM_SELF`
3808 .  m - number of rows
3809 .  n - number of columns
3810 .  nz - number of nonzeros per row (same for all rows)
3811 -  nnz - array containing the number of nonzeros in the various rows
3812          (possibly different for each row) or NULL
3813 
3814    Output Parameter:
3815 .  A - the matrix
3816 
3817    It is recommended that one use the `MatCreate()`, `MatSetType()` and/or `MatSetFromOptions()`,
3818    MatXXXXSetPreallocation() paradigm instead of this routine directly.
3819    [MatXXXXSetPreallocation() is, for example, `MatSeqAIJSetPreallocation()`]
3820 
3821    Notes:
3822    If nnz is given then nz is ignored
3823 
3824    The AIJ format, also called
3825    compressed row storage, is fully compatible with standard Fortran 77
3826    storage.  That is, the stored row and column indices can begin at
3827    either one (as in Fortran) or zero.  See the users' manual for details.
3828 
3829    Specify the preallocated storage with either nz or nnz (not both).
3830    Set nz = `PETSC_DEFAULT` and nnz = NULL for PETSc to control dynamic memory
3831    allocation.  For large problems you MUST preallocate memory or you
3832    will get TERRIBLE performance, see the users' manual chapter on matrices.
3833 
3834    By default, this format uses inodes (identical nodes) when possible, to
3835    improve numerical efficiency of matrix-vector products and solves. We
3836    search for consecutive rows with the same nonzero structure, thereby
3837    reusing matrix information to achieve increased efficiency.
3838 
3839    Options Database Keys:
3840 +  -mat_no_inode  - Do not use inodes
3841 -  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
3842 
3843    Level: intermediate
3844 
3845 .seealso: [Sparse Matrix Creation](sec_matsparse), `MatCreate()`, `MatCreateAIJ()`, `MatSetValues()`, `MatSeqAIJSetColumnIndices()`, `MatCreateSeqAIJWithArrays()`
3846 @*/
3847 PetscErrorCode MatCreateSeqAIJ(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt nz, const PetscInt nnz[], Mat *A)
3848 {
3849   PetscFunctionBegin;
3850   PetscCall(MatCreate(comm, A));
3851   PetscCall(MatSetSizes(*A, m, n, m, n));
3852   PetscCall(MatSetType(*A, MATSEQAIJ));
3853   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*A, nz, nnz));
3854   PetscFunctionReturn(0);
3855 }
3856 
3857 /*@C
3858    MatSeqAIJSetPreallocation - For good matrix assembly performance
3859    the user should preallocate the matrix storage by setting the parameter nz
3860    (or the array nnz).  By setting these parameters accurately, performance
3861    during matrix assembly can be increased by more than a factor of 50.
3862 
3863    Collective
3864 
3865    Input Parameters:
3866 +  B - The matrix
3867 .  nz - number of nonzeros per row (same for all rows)
3868 -  nnz - array containing the number of nonzeros in the various rows
3869          (possibly different for each row) or NULL
3870 
3871    Notes:
3872      If nnz is given then nz is ignored
3873 
3874     The `MATSEQAIJ` format also called
3875    compressed row storage, is fully compatible with standard Fortran 77
3876    storage.  That is, the stored row and column indices can begin at
3877    either one (as in Fortran) or zero.  See the users' manual for details.
3878 
3879    Specify the preallocated storage with either nz or nnz (not both).
3880    Set nz = `PETSC_DEFAULT` and nnz = NULL for PETSc to control dynamic memory
3881    allocation.  For large problems you MUST preallocate memory or you
3882    will get TERRIBLE performance, see the users' manual chapter on matrices.
3883 
3884    You can call `MatGetInfo()` to get information on how effective the preallocation was;
3885    for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3886    You can also run with the option -info and look for messages with the string
3887    malloc in them to see if additional memory allocation was needed.
3888 
3889    Developer Notes:
3890    Use nz of `MAT_SKIP_ALLOCATION` to not allocate any space for the matrix
3891    entries or columns indices
3892 
3893    By default, this format uses inodes (identical nodes) when possible, to
3894    improve numerical efficiency of matrix-vector products and solves. We
3895    search for consecutive rows with the same nonzero structure, thereby
3896    reusing matrix information to achieve increased efficiency.
3897 
3898    Options Database Keys:
3899 +  -mat_no_inode  - Do not use inodes
3900 -  -mat_inode_limit <limit> - Sets inode limit (max limit=5)
3901 
3902    Level: intermediate
3903 
3904 .seealso: `MatCreate()`, `MatCreateAIJ()`, `MatSetValues()`, `MatSeqAIJSetColumnIndices()`, `MatCreateSeqAIJWithArrays()`, `MatGetInfo()`,
3905           `MatSeqAIJSetTotalPreallocation()`
3906 @*/
3907 PetscErrorCode MatSeqAIJSetPreallocation(Mat B, PetscInt nz, const PetscInt nnz[])
3908 {
3909   PetscFunctionBegin;
3910   PetscValidHeaderSpecific(B, MAT_CLASSID, 1);
3911   PetscValidType(B, 1);
3912   PetscTryMethod(B, "MatSeqAIJSetPreallocation_C", (Mat, PetscInt, const PetscInt[]), (B, nz, nnz));
3913   PetscFunctionReturn(0);
3914 }
3915 
3916 PetscErrorCode MatSeqAIJSetPreallocation_SeqAIJ(Mat B, PetscInt nz, const PetscInt *nnz)
3917 {
3918   Mat_SeqAIJ *b;
3919   PetscBool   skipallocation = PETSC_FALSE, realalloc = PETSC_FALSE;
3920   PetscInt    i;
3921 
3922   PetscFunctionBegin;
3923   if (nz >= 0 || nnz) realalloc = PETSC_TRUE;
3924   if (nz == MAT_SKIP_ALLOCATION) {
3925     skipallocation = PETSC_TRUE;
3926     nz             = 0;
3927   }
3928   PetscCall(PetscLayoutSetUp(B->rmap));
3929   PetscCall(PetscLayoutSetUp(B->cmap));
3930 
3931   if (nz == PETSC_DEFAULT || nz == PETSC_DECIDE) nz = 5;
3932   PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "nz cannot be less than 0: value %" PetscInt_FMT, nz);
3933   if (PetscUnlikelyDebug(nnz)) {
3934     for (i = 0; i < B->rmap->n; i++) {
3935       PetscCheck(nnz[i] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "nnz cannot be less than 0: local row %" PetscInt_FMT " value %" PetscInt_FMT, i, nnz[i]);
3936       PetscCheck(nnz[i] <= B->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "nnz cannot be greater than row length: local row %" PetscInt_FMT " value %" PetscInt_FMT " rowlength %" PetscInt_FMT, i, nnz[i], B->cmap->n);
3937     }
3938   }
3939 
3940   B->preallocated = PETSC_TRUE;
3941 
3942   b = (Mat_SeqAIJ *)B->data;
3943 
3944   if (!skipallocation) {
3945     if (!b->imax) { PetscCall(PetscMalloc1(B->rmap->n, &b->imax)); }
3946     if (!b->ilen) {
3947       /* b->ilen will count nonzeros in each row so far. */
3948       PetscCall(PetscCalloc1(B->rmap->n, &b->ilen));
3949     } else {
3950       PetscCall(PetscMemzero(b->ilen, B->rmap->n * sizeof(PetscInt)));
3951     }
3952     if (!b->ipre) { PetscCall(PetscMalloc1(B->rmap->n, &b->ipre)); }
3953     if (!nnz) {
3954       if (nz == PETSC_DEFAULT || nz == PETSC_DECIDE) nz = 10;
3955       else if (nz < 0) nz = 1;
3956       nz = PetscMin(nz, B->cmap->n);
3957       for (i = 0; i < B->rmap->n; i++) b->imax[i] = nz;
3958       nz = nz * B->rmap->n;
3959     } else {
3960       PetscInt64 nz64 = 0;
3961       for (i = 0; i < B->rmap->n; i++) {
3962         b->imax[i] = nnz[i];
3963         nz64 += nnz[i];
3964       }
3965       PetscCall(PetscIntCast(nz64, &nz));
3966     }
3967 
3968     /* allocate the matrix space */
3969     /* FIXME: should B's old memory be unlogged? */
3970     PetscCall(MatSeqXAIJFreeAIJ(B, &b->a, &b->j, &b->i));
3971     if (B->structure_only) {
3972       PetscCall(PetscMalloc1(nz, &b->j));
3973       PetscCall(PetscMalloc1(B->rmap->n + 1, &b->i));
3974     } else {
3975       PetscCall(PetscMalloc3(nz, &b->a, nz, &b->j, B->rmap->n + 1, &b->i));
3976     }
3977     b->i[0] = 0;
3978     for (i = 1; i < B->rmap->n + 1; i++) b->i[i] = b->i[i - 1] + b->imax[i - 1];
3979     if (B->structure_only) {
3980       b->singlemalloc = PETSC_FALSE;
3981       b->free_a       = PETSC_FALSE;
3982     } else {
3983       b->singlemalloc = PETSC_TRUE;
3984       b->free_a       = PETSC_TRUE;
3985     }
3986     b->free_ij = PETSC_TRUE;
3987   } else {
3988     b->free_a  = PETSC_FALSE;
3989     b->free_ij = PETSC_FALSE;
3990   }
3991 
3992   if (b->ipre && nnz != b->ipre && b->imax) {
3993     /* reserve user-requested sparsity */
3994     PetscCall(PetscArraycpy(b->ipre, b->imax, B->rmap->n));
3995   }
3996 
3997   b->nz               = 0;
3998   b->maxnz            = nz;
3999   B->info.nz_unneeded = (double)b->maxnz;
4000   if (realalloc) PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_TRUE));
4001   B->was_assembled = PETSC_FALSE;
4002   B->assembled     = PETSC_FALSE;
4003   /* We simply deem preallocation has changed nonzero state. Updating the state
4004      will give clients (like AIJKokkos) a chance to know something has happened.
4005   */
4006   B->nonzerostate++;
4007   PetscFunctionReturn(0);
4008 }
4009 
4010 PetscErrorCode MatResetPreallocation_SeqAIJ(Mat A)
4011 {
4012   Mat_SeqAIJ *a;
4013   PetscInt    i;
4014 
4015   PetscFunctionBegin;
4016   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
4017 
4018   /* Check local size. If zero, then return */
4019   if (!A->rmap->n) PetscFunctionReturn(0);
4020 
4021   a = (Mat_SeqAIJ *)A->data;
4022   /* if no saved info, we error out */
4023   PetscCheck(a->ipre, PETSC_COMM_SELF, PETSC_ERR_ARG_NULL, "No saved preallocation info ");
4024 
4025   PetscCheck(a->i && a->j && a->a && a->imax && a->ilen, PETSC_COMM_SELF, PETSC_ERR_ARG_NULL, "Memory info is incomplete, and can not reset preallocation ");
4026 
4027   PetscCall(PetscArraycpy(a->imax, a->ipre, A->rmap->n));
4028   PetscCall(PetscArrayzero(a->ilen, A->rmap->n));
4029   a->i[0] = 0;
4030   for (i = 1; i < A->rmap->n + 1; i++) a->i[i] = a->i[i - 1] + a->imax[i - 1];
4031   A->preallocated     = PETSC_TRUE;
4032   a->nz               = 0;
4033   a->maxnz            = a->i[A->rmap->n];
4034   A->info.nz_unneeded = (double)a->maxnz;
4035   A->was_assembled    = PETSC_FALSE;
4036   A->assembled        = PETSC_FALSE;
4037   PetscFunctionReturn(0);
4038 }
4039 
4040 /*@
4041    MatSeqAIJSetPreallocationCSR - Allocates memory for a sparse sequential matrix in `MATSEQAIJ` format.
4042 
4043    Input Parameters:
4044 +  B - the matrix
4045 .  i - the indices into j for the start of each row (starts with zero)
4046 .  j - the column indices for each row (starts with zero) these must be sorted for each row
4047 -  v - optional values in the matrix
4048 
4049    Level: developer
4050 
4051    Notes:
4052       The i,j,v values are COPIED with this routine; to avoid the copy use `MatCreateSeqAIJWithArrays()`
4053 
4054       This routine may be called multiple times with different nonzero patterns (or the same nonzero pattern). The nonzero
4055       structure will be the union of all the previous nonzero structures.
4056 
4057     Developer Notes:
4058       An optimization could be added to the implementation where it checks if the i, and j are identical to the current i and j and
4059       then just copies the v values directly with `PetscMemcpy()`.
4060 
4061       This routine could also take a `PetscCopyMode` argument to allow sharing the values instead of always copying them.
4062 
4063 .seealso: `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatSeqAIJSetPreallocation()`, `MatCreateSeqAIJ()`, `MATSEQAIJ`, `MatResetPreallocation()`
4064 @*/
4065 PetscErrorCode MatSeqAIJSetPreallocationCSR(Mat B, const PetscInt i[], const PetscInt j[], const PetscScalar v[])
4066 {
4067   PetscFunctionBegin;
4068   PetscValidHeaderSpecific(B, MAT_CLASSID, 1);
4069   PetscValidType(B, 1);
4070   PetscTryMethod(B, "MatSeqAIJSetPreallocationCSR_C", (Mat, const PetscInt[], const PetscInt[], const PetscScalar[]), (B, i, j, v));
4071   PetscFunctionReturn(0);
4072 }
4073 
4074 PetscErrorCode MatSeqAIJSetPreallocationCSR_SeqAIJ(Mat B, const PetscInt Ii[], const PetscInt J[], const PetscScalar v[])
4075 {
4076   PetscInt  i;
4077   PetscInt  m, n;
4078   PetscInt  nz;
4079   PetscInt *nnz;
4080 
4081   PetscFunctionBegin;
4082   PetscCheck(Ii[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Ii[0] must be 0 it is %" PetscInt_FMT, Ii[0]);
4083 
4084   PetscCall(PetscLayoutSetUp(B->rmap));
4085   PetscCall(PetscLayoutSetUp(B->cmap));
4086 
4087   PetscCall(MatGetSize(B, &m, &n));
4088   PetscCall(PetscMalloc1(m + 1, &nnz));
4089   for (i = 0; i < m; i++) {
4090     nz = Ii[i + 1] - Ii[i];
4091     PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local row %" PetscInt_FMT " has a negative number of columns %" PetscInt_FMT, i, nz);
4092     nnz[i] = nz;
4093   }
4094   PetscCall(MatSeqAIJSetPreallocation(B, 0, nnz));
4095   PetscCall(PetscFree(nnz));
4096 
4097   for (i = 0; i < m; i++) PetscCall(MatSetValues_SeqAIJ(B, 1, &i, Ii[i + 1] - Ii[i], J + Ii[i], v ? v + Ii[i] : NULL, INSERT_VALUES));
4098 
4099   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
4100   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
4101 
4102   PetscCall(MatSetOption(B, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
4103   PetscFunctionReturn(0);
4104 }
4105 
4106 /*@
4107    MatSeqAIJKron - Computes C, the Kronecker product of A and B.
4108 
4109    Input Parameters:
4110 +  A - left-hand side matrix
4111 .  B - right-hand side matrix
4112 -  reuse - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
4113 
4114    Output Parameter:
4115 .  C - Kronecker product of A and B
4116 
4117    Level: intermediate
4118 
4119    Note:
4120       `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the product matrix has not changed from that last call to `MatSeqAIJKron()`.
4121 
4122 .seealso: `MatCreateSeqAIJ()`, `MATSEQAIJ`, `MATKAIJ`, `MatReuse`
4123 @*/
4124 PetscErrorCode MatSeqAIJKron(Mat A, Mat B, MatReuse reuse, Mat *C)
4125 {
4126   PetscFunctionBegin;
4127   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
4128   PetscValidType(A, 1);
4129   PetscValidHeaderSpecific(B, MAT_CLASSID, 2);
4130   PetscValidType(B, 2);
4131   PetscValidPointer(C, 4);
4132   if (reuse == MAT_REUSE_MATRIX) {
4133     PetscValidHeaderSpecific(*C, MAT_CLASSID, 4);
4134     PetscValidType(*C, 4);
4135   }
4136   PetscTryMethod(A, "MatSeqAIJKron_C", (Mat, Mat, MatReuse, Mat *), (A, B, reuse, C));
4137   PetscFunctionReturn(0);
4138 }
4139 
4140 PetscErrorCode MatSeqAIJKron_SeqAIJ(Mat A, Mat B, MatReuse reuse, Mat *C)
4141 {
4142   Mat                newmat;
4143   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
4144   Mat_SeqAIJ        *b = (Mat_SeqAIJ *)B->data;
4145   PetscScalar       *v;
4146   const PetscScalar *aa, *ba;
4147   PetscInt          *i, *j, m, n, p, q, nnz = 0, am = A->rmap->n, bm = B->rmap->n, an = A->cmap->n, bn = B->cmap->n;
4148   PetscBool          flg;
4149 
4150   PetscFunctionBegin;
4151   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4152   PetscCheck(A->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4153   PetscCheck(!B->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4154   PetscCheck(B->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4155   PetscCall(PetscObjectTypeCompare((PetscObject)B, MATSEQAIJ, &flg));
4156   PetscCheck(flg, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatType %s", ((PetscObject)B)->type_name);
4157   PetscCheck(reuse == MAT_INITIAL_MATRIX || reuse == MAT_REUSE_MATRIX, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatReuse %d", (int)reuse);
4158   if (reuse == MAT_INITIAL_MATRIX) {
4159     PetscCall(PetscMalloc2(am * bm + 1, &i, a->i[am] * b->i[bm], &j));
4160     PetscCall(MatCreate(PETSC_COMM_SELF, &newmat));
4161     PetscCall(MatSetSizes(newmat, am * bm, an * bn, am * bm, an * bn));
4162     PetscCall(MatSetType(newmat, MATAIJ));
4163     i[0] = 0;
4164     for (m = 0; m < am; ++m) {
4165       for (p = 0; p < bm; ++p) {
4166         i[m * bm + p + 1] = i[m * bm + p] + (a->i[m + 1] - a->i[m]) * (b->i[p + 1] - b->i[p]);
4167         for (n = a->i[m]; n < a->i[m + 1]; ++n) {
4168           for (q = b->i[p]; q < b->i[p + 1]; ++q) j[nnz++] = a->j[n] * bn + b->j[q];
4169         }
4170       }
4171     }
4172     PetscCall(MatSeqAIJSetPreallocationCSR(newmat, i, j, NULL));
4173     *C = newmat;
4174     PetscCall(PetscFree2(i, j));
4175     nnz = 0;
4176   }
4177   PetscCall(MatSeqAIJGetArray(*C, &v));
4178   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
4179   PetscCall(MatSeqAIJGetArrayRead(B, &ba));
4180   for (m = 0; m < am; ++m) {
4181     for (p = 0; p < bm; ++p) {
4182       for (n = a->i[m]; n < a->i[m + 1]; ++n) {
4183         for (q = b->i[p]; q < b->i[p + 1]; ++q) v[nnz++] = aa[n] * ba[q];
4184       }
4185     }
4186   }
4187   PetscCall(MatSeqAIJRestoreArray(*C, &v));
4188   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
4189   PetscCall(MatSeqAIJRestoreArrayRead(B, &ba));
4190   PetscFunctionReturn(0);
4191 }
4192 
4193 #include <../src/mat/impls/dense/seq/dense.h>
4194 #include <petsc/private/kernels/petscaxpy.h>
4195 
4196 /*
4197     Computes (B'*A')' since computing B*A directly is untenable
4198 
4199                n                       p                          p
4200         [             ]       [             ]         [                 ]
4201       m [      A      ]  *  n [       B     ]   =   m [         C       ]
4202         [             ]       [             ]         [                 ]
4203 
4204 */
4205 PetscErrorCode MatMatMultNumeric_SeqDense_SeqAIJ(Mat A, Mat B, Mat C)
4206 {
4207   Mat_SeqDense      *sub_a = (Mat_SeqDense *)A->data;
4208   Mat_SeqAIJ        *sub_b = (Mat_SeqAIJ *)B->data;
4209   Mat_SeqDense      *sub_c = (Mat_SeqDense *)C->data;
4210   PetscInt           i, j, n, m, q, p;
4211   const PetscInt    *ii, *idx;
4212   const PetscScalar *b, *a, *a_q;
4213   PetscScalar       *c, *c_q;
4214   PetscInt           clda = sub_c->lda;
4215   PetscInt           alda = sub_a->lda;
4216 
4217   PetscFunctionBegin;
4218   m = A->rmap->n;
4219   n = A->cmap->n;
4220   p = B->cmap->n;
4221   a = sub_a->v;
4222   b = sub_b->a;
4223   c = sub_c->v;
4224   if (clda == m) {
4225     PetscCall(PetscArrayzero(c, m * p));
4226   } else {
4227     for (j = 0; j < p; j++)
4228       for (i = 0; i < m; i++) c[j * clda + i] = 0.0;
4229   }
4230   ii  = sub_b->i;
4231   idx = sub_b->j;
4232   for (i = 0; i < n; i++) {
4233     q = ii[i + 1] - ii[i];
4234     while (q-- > 0) {
4235       c_q = c + clda * (*idx);
4236       a_q = a + alda * i;
4237       PetscKernelAXPY(c_q, *b, a_q, m);
4238       idx++;
4239       b++;
4240     }
4241   }
4242   PetscFunctionReturn(0);
4243 }
4244 
4245 PetscErrorCode MatMatMultSymbolic_SeqDense_SeqAIJ(Mat A, Mat B, PetscReal fill, Mat C)
4246 {
4247   PetscInt  m = A->rmap->n, n = B->cmap->n;
4248   PetscBool cisdense;
4249 
4250   PetscFunctionBegin;
4251   PetscCheck(A->cmap->n == B->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "A->cmap->n %" PetscInt_FMT " != B->rmap->n %" PetscInt_FMT, A->cmap->n, B->rmap->n);
4252   PetscCall(MatSetSizes(C, m, n, m, n));
4253   PetscCall(MatSetBlockSizesFromMats(C, A, B));
4254   PetscCall(PetscObjectTypeCompareAny((PetscObject)C, &cisdense, MATSEQDENSE, MATSEQDENSECUDA, ""));
4255   if (!cisdense) PetscCall(MatSetType(C, MATDENSE));
4256   PetscCall(MatSetUp(C));
4257 
4258   C->ops->matmultnumeric = MatMatMultNumeric_SeqDense_SeqAIJ;
4259   PetscFunctionReturn(0);
4260 }
4261 
4262 /* ----------------------------------------------------------------*/
4263 /*MC
4264    MATSEQAIJ - MATSEQAIJ = "seqaij" - A matrix type to be used for sequential sparse matrices,
4265    based on compressed sparse row format.
4266 
4267    Options Database Keys:
4268 . -mat_type seqaij - sets the matrix type to "seqaij" during a call to MatSetFromOptions()
4269 
4270    Level: beginner
4271 
4272    Notes:
4273     `MatSetValues()` may be called for this matrix type with a NULL argument for the numerical values,
4274     in this case the values associated with the rows and columns one passes in are set to zero
4275     in the matrix
4276 
4277     `MatSetOptions`(,`MAT_STRUCTURE_ONLY`,`PETSC_TRUE`) may be called for this matrix type. In this no
4278     space is allocated for the nonzero entries and any entries passed with `MatSetValues()` are ignored
4279 
4280   Developer Note:
4281     It would be nice if all matrix formats supported passing NULL in for the numerical values
4282 
4283 .seealso: `MatCreateSeqAIJ()`, `MatSetFromOptions()`, `MatSetType()`, `MatCreate()`, `MatType`, `MATSELL`, `MATSEQSELL`, `MATMPISELL`
4284 M*/
4285 
4286 /*MC
4287    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.
4288 
4289    This matrix type is identical to `MATSEQAIJ` when constructed with a single process communicator,
4290    and `MATMPIAIJ` otherwise.  As a result, for single process communicators,
4291    `MatSeqAIJSetPreallocation()` is supported, and similarly `MatMPIAIJSetPreallocation()` is supported
4292    for communicators controlling multiple processes.  It is recommended that you call both of
4293    the above preallocation routines for simplicity.
4294 
4295    Options Database Keys:
4296 . -mat_type aij - sets the matrix type to "aij" during a call to `MatSetFromOptions()`
4297 
4298    Note:
4299    Subclasses include `MATAIJCUSPARSE`, `MATAIJPERM`, `MATAIJSELL`, `MATAIJMKL`, `MATAIJCRL`, and also automatically switches over to use inodes when
4300    enough exist.
4301 
4302   Level: beginner
4303 
4304 .seealso: `MatCreateAIJ()`, `MatCreateSeqAIJ()`, `MATSEQAIJ`, `MATMPIAIJ`, `MATSELL`, `MATSEQSELL`, `MATMPISELL`
4305 M*/
4306 
4307 /*MC
4308    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.
4309 
4310    This matrix type is identical to `MATSEQAIJCRL` when constructed with a single process communicator,
4311    and `MATMPIAIJCRL` otherwise.  As a result, for single process communicators,
4312    `MatSeqAIJSetPreallocation()` is supported, and similarly `MatMPIAIJSetPreallocation()` is supported
4313    for communicators controlling multiple processes.  It is recommended that you call both of
4314    the above preallocation routines for simplicity.
4315 
4316    Options Database Keys:
4317 . -mat_type aijcrl - sets the matrix type to "aijcrl" during a call to `MatSetFromOptions()`
4318 
4319   Level: beginner
4320 
4321 .seealso: `MatCreateMPIAIJCRL`, `MATSEQAIJCRL`, `MATMPIAIJCRL`, `MATSEQAIJCRL`, `MATMPIAIJCRL`
4322 M*/
4323 
4324 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJCRL(Mat, MatType, MatReuse, Mat *);
4325 #if defined(PETSC_HAVE_ELEMENTAL)
4326 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_Elemental(Mat, MatType, MatReuse, Mat *);
4327 #endif
4328 #if defined(PETSC_HAVE_SCALAPACK)
4329 PETSC_INTERN PetscErrorCode MatConvert_AIJ_ScaLAPACK(Mat, MatType, MatReuse, Mat *);
4330 #endif
4331 #if defined(PETSC_HAVE_HYPRE)
4332 PETSC_INTERN PetscErrorCode MatConvert_AIJ_HYPRE(Mat A, MatType, MatReuse, Mat *);
4333 #endif
4334 
4335 PETSC_EXTERN PetscErrorCode MatConvert_SeqAIJ_SeqSELL(Mat, MatType, MatReuse, Mat *);
4336 PETSC_INTERN PetscErrorCode MatConvert_XAIJ_IS(Mat, MatType, MatReuse, Mat *);
4337 PETSC_INTERN PetscErrorCode MatProductSetFromOptions_IS_XAIJ(Mat);
4338 
4339 /*@C
4340    MatSeqAIJGetArray - gives read/write access to the array where the data for a `MATSEQAIJ` matrix is stored
4341 
4342    Not Collective
4343 
4344    Input Parameter:
4345 .  mat - a `MATSEQAIJ` matrix
4346 
4347    Output Parameter:
4348 .   array - pointer to the data
4349 
4350    Level: intermediate
4351 
4352 .seealso: `MatSeqAIJRestoreArray()`, `MatSeqAIJGetArrayF90()`
4353 @*/
4354 PetscErrorCode MatSeqAIJGetArray(Mat A, PetscScalar **array)
4355 {
4356   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4357 
4358   PetscFunctionBegin;
4359   if (aij->ops->getarray) {
4360     PetscCall((*aij->ops->getarray)(A, array));
4361   } else {
4362     *array = aij->a;
4363   }
4364   PetscFunctionReturn(0);
4365 }
4366 
4367 /*@C
4368    MatSeqAIJRestoreArray - returns access to the array where the data for a `MATSEQAIJ` matrix is stored obtained by `MatSeqAIJGetArray()`
4369 
4370    Not Collective
4371 
4372    Input Parameters:
4373 +  mat - a `MATSEQAIJ` matrix
4374 -  array - pointer to the data
4375 
4376    Level: intermediate
4377 
4378 .seealso: `MatSeqAIJGetArray()`, `MatSeqAIJRestoreArrayF90()`
4379 @*/
4380 PetscErrorCode MatSeqAIJRestoreArray(Mat A, PetscScalar **array)
4381 {
4382   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4383 
4384   PetscFunctionBegin;
4385   if (aij->ops->restorearray) {
4386     PetscCall((*aij->ops->restorearray)(A, array));
4387   } else {
4388     *array = NULL;
4389   }
4390   PetscCall(MatSeqAIJInvalidateDiagonal(A));
4391   PetscCall(PetscObjectStateIncrease((PetscObject)A));
4392   PetscFunctionReturn(0);
4393 }
4394 
4395 /*@C
4396    MatSeqAIJGetArrayRead - gives read-only access to the array where the data for a `MATSEQAIJ` matrix is stored
4397 
4398    Not Collective
4399 
4400    Input Parameter:
4401 .  mat - a `MATSEQAIJ` matrix
4402 
4403    Output Parameter:
4404 .   array - pointer to the data
4405 
4406    Level: intermediate
4407 
4408 .seealso: `MatSeqAIJGetArray()`, `MatSeqAIJRestoreArrayRead()`
4409 @*/
4410 PetscErrorCode MatSeqAIJGetArrayRead(Mat A, const PetscScalar **array)
4411 {
4412   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4413 
4414   PetscFunctionBegin;
4415   if (aij->ops->getarrayread) {
4416     PetscCall((*aij->ops->getarrayread)(A, array));
4417   } else {
4418     *array = aij->a;
4419   }
4420   PetscFunctionReturn(0);
4421 }
4422 
4423 /*@C
4424    MatSeqAIJRestoreArrayRead - restore the read-only access array obtained from `MatSeqAIJGetArrayRead()`
4425 
4426    Not Collective
4427 
4428    Input Parameter:
4429 .  mat - a `MATSEQAIJ` matrix
4430 
4431    Output Parameter:
4432 .   array - pointer to the data
4433 
4434    Level: intermediate
4435 
4436 .seealso: `MatSeqAIJGetArray()`, `MatSeqAIJGetArrayRead()`
4437 @*/
4438 PetscErrorCode MatSeqAIJRestoreArrayRead(Mat A, const PetscScalar **array)
4439 {
4440   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4441 
4442   PetscFunctionBegin;
4443   if (aij->ops->restorearrayread) {
4444     PetscCall((*aij->ops->restorearrayread)(A, array));
4445   } else {
4446     *array = NULL;
4447   }
4448   PetscFunctionReturn(0);
4449 }
4450 
4451 /*@C
4452    MatSeqAIJGetArrayWrite - gives write-only access to the array where the data for a `MATSEQAIJ` matrix is stored
4453 
4454    Not Collective
4455 
4456    Input Parameter:
4457 .  mat - a `MATSEQAIJ` matrix
4458 
4459    Output Parameter:
4460 .   array - pointer to the data
4461 
4462    Level: intermediate
4463 
4464 .seealso: `MatSeqAIJGetArray()`, `MatSeqAIJRestoreArrayRead()`
4465 @*/
4466 PetscErrorCode MatSeqAIJGetArrayWrite(Mat A, PetscScalar **array)
4467 {
4468   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4469 
4470   PetscFunctionBegin;
4471   if (aij->ops->getarraywrite) {
4472     PetscCall((*aij->ops->getarraywrite)(A, array));
4473   } else {
4474     *array = aij->a;
4475   }
4476   PetscCall(MatSeqAIJInvalidateDiagonal(A));
4477   PetscCall(PetscObjectStateIncrease((PetscObject)A));
4478   PetscFunctionReturn(0);
4479 }
4480 
4481 /*@C
4482    MatSeqAIJRestoreArrayWrite - restore the read-only access array obtained from MatSeqAIJGetArrayRead
4483 
4484    Not Collective
4485 
4486    Input Parameter:
4487 .  mat - a MATSEQAIJ matrix
4488 
4489    Output Parameter:
4490 .   array - pointer to the data
4491 
4492    Level: intermediate
4493 
4494 .seealso: `MatSeqAIJGetArray()`, `MatSeqAIJGetArrayRead()`
4495 @*/
4496 PetscErrorCode MatSeqAIJRestoreArrayWrite(Mat A, PetscScalar **array)
4497 {
4498   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4499 
4500   PetscFunctionBegin;
4501   if (aij->ops->restorearraywrite) {
4502     PetscCall((*aij->ops->restorearraywrite)(A, array));
4503   } else {
4504     *array = NULL;
4505   }
4506   PetscFunctionReturn(0);
4507 }
4508 
4509 /*@C
4510    MatSeqAIJGetCSRAndMemType - Get the CSR arrays and the memory type of the `MATSEQAIJ` matrix
4511 
4512    Not Collective
4513 
4514    Input Parameter:
4515 .  mat - a matrix of type `MATSEQAIJ` or its subclasses
4516 
4517    Output Parameters:
4518 +  i - row map array of the matrix
4519 .  j - column index array of the matrix
4520 .  a - data array of the matrix
4521 -  memtype - memory type of the arrays
4522 
4523   Notes:
4524    Any of the output parameters can be NULL, in which case the corresponding value is not returned.
4525    If mat is a device matrix, the arrays are on the device. Otherwise, they are on the host.
4526 
4527    One can call this routine on a preallocated but not assembled matrix to just get the memory of the CSR underneath the matrix.
4528    If the matrix is assembled, the data array 'a' is guaranteed to have the latest values of the matrix.
4529 
4530    Level: Developer
4531 
4532 .seealso: `MatSeqAIJGetArray()`, `MatSeqAIJGetArrayRead()`
4533 @*/
4534 PetscErrorCode MatSeqAIJGetCSRAndMemType(Mat mat, const PetscInt **i, const PetscInt **j, PetscScalar **a, PetscMemType *mtype)
4535 {
4536   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)mat->data;
4537 
4538   PetscFunctionBegin;
4539   PetscCheck(mat->preallocated, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "matrix is not preallocated");
4540   if (aij->ops->getcsrandmemtype) {
4541     PetscCall((*aij->ops->getcsrandmemtype)(mat, i, j, a, mtype));
4542   } else {
4543     if (i) *i = aij->i;
4544     if (j) *j = aij->j;
4545     if (a) *a = aij->a;
4546     if (mtype) *mtype = PETSC_MEMTYPE_HOST;
4547   }
4548   PetscFunctionReturn(0);
4549 }
4550 
4551 /*@C
4552    MatSeqAIJGetMaxRowNonzeros - returns the maximum number of nonzeros in any row
4553 
4554    Not Collective
4555 
4556    Input Parameter:
4557 .  mat - a `MATSEQAIJ` matrix
4558 
4559    Output Parameter:
4560 .   nz - the maximum number of nonzeros in any row
4561 
4562    Level: intermediate
4563 
4564 .seealso: `MatSeqAIJRestoreArray()`, `MatSeqAIJGetArrayF90()`
4565 @*/
4566 PetscErrorCode MatSeqAIJGetMaxRowNonzeros(Mat A, PetscInt *nz)
4567 {
4568   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4569 
4570   PetscFunctionBegin;
4571   *nz = aij->rmax;
4572   PetscFunctionReturn(0);
4573 }
4574 
4575 PetscErrorCode MatSetPreallocationCOO_SeqAIJ(Mat mat, PetscCount coo_n, PetscInt coo_i[], PetscInt coo_j[])
4576 {
4577   MPI_Comm     comm;
4578   PetscInt    *i, *j;
4579   PetscInt     M, N, row;
4580   PetscCount   k, p, q, nneg, nnz, start, end; /* Index the coo array, so use PetscCount as their type */
4581   PetscInt    *Ai;                             /* Change to PetscCount once we use it for row pointers */
4582   PetscInt    *Aj;
4583   PetscScalar *Aa;
4584   Mat_SeqAIJ  *seqaij = (Mat_SeqAIJ *)(mat->data);
4585   MatType      rtype;
4586   PetscCount  *perm, *jmap;
4587 
4588   PetscFunctionBegin;
4589   PetscCall(MatResetPreallocationCOO_SeqAIJ(mat));
4590   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
4591   PetscCall(MatGetSize(mat, &M, &N));
4592   i = coo_i;
4593   j = coo_j;
4594   PetscCall(PetscMalloc1(coo_n, &perm));
4595   for (k = 0; k < coo_n; k++) { /* Ignore entries with negative row or col indices */
4596     if (j[k] < 0) i[k] = -1;
4597     perm[k] = k;
4598   }
4599 
4600   /* Sort by row */
4601   PetscCall(PetscSortIntWithIntCountArrayPair(coo_n, i, j, perm));
4602   for (k = 0; k < coo_n; k++) {
4603     if (i[k] >= 0) break;
4604   } /* Advance k to the first row with a non-negative index */
4605   nneg = k;
4606   PetscCall(PetscMalloc1(coo_n - nneg + 1, &jmap)); /* +1 to make a CSR-like data structure. jmap[i] originally is the number of repeats for i-th nonzero */
4607   nnz = 0;                                          /* Total number of unique nonzeros to be counted */
4608   jmap++;                                           /* Inc jmap by 1 for convinience */
4609 
4610   PetscCall(PetscCalloc1(M + 1, &Ai));        /* CSR of A */
4611   PetscCall(PetscMalloc1(coo_n - nneg, &Aj)); /* We have at most coo_n-nneg unique nonzeros */
4612 
4613   /* In each row, sort by column, then unique column indices to get row length */
4614   Ai++;  /* Inc by 1 for convinience */
4615   q = 0; /* q-th unique nonzero, with q starting from 0 */
4616   while (k < coo_n) {
4617     row   = i[k];
4618     start = k; /* [start,end) indices for this row */
4619     while (k < coo_n && i[k] == row) k++;
4620     end = k;
4621     PetscCall(PetscSortIntWithCountArray(end - start, j + start, perm + start));
4622     /* Find number of unique col entries in this row */
4623     Aj[q]   = j[start]; /* Log the first nonzero in this row */
4624     jmap[q] = 1;        /* Number of repeats of this nozero entry */
4625     Ai[row] = 1;
4626     nnz++;
4627 
4628     for (p = start + 1; p < end; p++) { /* Scan remaining nonzero in this row */
4629       if (j[p] != j[p - 1]) {           /* Meet a new nonzero */
4630         q++;
4631         jmap[q] = 1;
4632         Aj[q]   = j[p];
4633         Ai[row]++;
4634         nnz++;
4635       } else {
4636         jmap[q]++;
4637       }
4638     }
4639     q++; /* Move to next row and thus next unique nonzero */
4640   }
4641 
4642   Ai--; /* Back to the beginning of Ai[] */
4643   for (k = 0; k < M; k++) Ai[k + 1] += Ai[k];
4644   jmap--; /* Back to the beginning of jmap[] */
4645   jmap[0] = 0;
4646   for (k = 0; k < nnz; k++) jmap[k + 1] += jmap[k];
4647   if (nnz < coo_n - nneg) { /* Realloc with actual number of unique nonzeros */
4648     PetscCount *jmap_new;
4649     PetscInt   *Aj_new;
4650 
4651     PetscCall(PetscMalloc1(nnz + 1, &jmap_new));
4652     PetscCall(PetscArraycpy(jmap_new, jmap, nnz + 1));
4653     PetscCall(PetscFree(jmap));
4654     jmap = jmap_new;
4655 
4656     PetscCall(PetscMalloc1(nnz, &Aj_new));
4657     PetscCall(PetscArraycpy(Aj_new, Aj, nnz));
4658     PetscCall(PetscFree(Aj));
4659     Aj = Aj_new;
4660   }
4661 
4662   if (nneg) { /* Discard heading entries with negative indices in perm[], as we'll access it from index 0 in MatSetValuesCOO */
4663     PetscCount *perm_new;
4664 
4665     PetscCall(PetscMalloc1(coo_n - nneg, &perm_new));
4666     PetscCall(PetscArraycpy(perm_new, perm + nneg, coo_n - nneg));
4667     PetscCall(PetscFree(perm));
4668     perm = perm_new;
4669   }
4670 
4671   PetscCall(MatGetRootType_Private(mat, &rtype));
4672   PetscCall(PetscCalloc1(nnz, &Aa)); /* Zero the matrix */
4673   PetscCall(MatSetSeqAIJWithArrays_private(PETSC_COMM_SELF, M, N, Ai, Aj, Aa, rtype, mat));
4674 
4675   seqaij->singlemalloc = PETSC_FALSE;            /* Ai, Aj and Aa are not allocated in one big malloc */
4676   seqaij->free_a = seqaij->free_ij = PETSC_TRUE; /* Let newmat own Ai, Aj and Aa */
4677   /* Record COO fields */
4678   seqaij->coo_n = coo_n;
4679   seqaij->Atot  = coo_n - nneg; /* Annz is seqaij->nz, so no need to record that again */
4680   seqaij->jmap  = jmap;         /* of length nnz+1 */
4681   seqaij->perm  = perm;
4682   PetscFunctionReturn(0);
4683 }
4684 
4685 static PetscErrorCode MatSetValuesCOO_SeqAIJ(Mat A, const PetscScalar v[], InsertMode imode)
4686 {
4687   Mat_SeqAIJ  *aseq = (Mat_SeqAIJ *)A->data;
4688   PetscCount   i, j, Annz = aseq->nz;
4689   PetscCount  *perm = aseq->perm, *jmap = aseq->jmap;
4690   PetscScalar *Aa;
4691 
4692   PetscFunctionBegin;
4693   PetscCall(MatSeqAIJGetArray(A, &Aa));
4694   for (i = 0; i < Annz; i++) {
4695     PetscScalar sum = 0.0;
4696     for (j = jmap[i]; j < jmap[i + 1]; j++) sum += v[perm[j]];
4697     Aa[i] = (imode == INSERT_VALUES ? 0.0 : Aa[i]) + sum;
4698   }
4699   PetscCall(MatSeqAIJRestoreArray(A, &Aa));
4700   PetscFunctionReturn(0);
4701 }
4702 
4703 #if defined(PETSC_HAVE_CUDA)
4704 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJCUSPARSE(Mat, MatType, MatReuse, Mat *);
4705 #endif
4706 #if defined(PETSC_HAVE_KOKKOS_KERNELS)
4707 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJKokkos(Mat, MatType, MatReuse, Mat *);
4708 #endif
4709 
4710 PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJ(Mat B)
4711 {
4712   Mat_SeqAIJ *b;
4713   PetscMPIInt size;
4714 
4715   PetscFunctionBegin;
4716   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)B), &size));
4717   PetscCheck(size <= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Comm must be of size 1");
4718 
4719   PetscCall(PetscNew(&b));
4720 
4721   B->data = (void *)b;
4722 
4723   PetscCall(PetscMemcpy(B->ops, &MatOps_Values, sizeof(struct _MatOps)));
4724   if (B->sortedfull) B->ops->setvalues = MatSetValues_SeqAIJ_SortedFull;
4725 
4726   b->row                = NULL;
4727   b->col                = NULL;
4728   b->icol               = NULL;
4729   b->reallocs           = 0;
4730   b->ignorezeroentries  = PETSC_FALSE;
4731   b->roworiented        = PETSC_TRUE;
4732   b->nonew              = 0;
4733   b->diag               = NULL;
4734   b->solve_work         = NULL;
4735   B->spptr              = NULL;
4736   b->saved_values       = NULL;
4737   b->idiag              = NULL;
4738   b->mdiag              = NULL;
4739   b->ssor_work          = NULL;
4740   b->omega              = 1.0;
4741   b->fshift             = 0.0;
4742   b->idiagvalid         = PETSC_FALSE;
4743   b->ibdiagvalid        = PETSC_FALSE;
4744   b->keepnonzeropattern = PETSC_FALSE;
4745 
4746   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATSEQAIJ));
4747 #if defined(PETSC_HAVE_MATLAB)
4748   PetscCall(PetscObjectComposeFunction((PetscObject)B, "PetscMatlabEnginePut_C", MatlabEnginePut_SeqAIJ));
4749   PetscCall(PetscObjectComposeFunction((PetscObject)B, "PetscMatlabEngineGet_C", MatlabEngineGet_SeqAIJ));
4750 #endif
4751   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqAIJSetColumnIndices_C", MatSeqAIJSetColumnIndices_SeqAIJ));
4752   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatStoreValues_C", MatStoreValues_SeqAIJ));
4753   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatRetrieveValues_C", MatRetrieveValues_SeqAIJ));
4754   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqsbaij_C", MatConvert_SeqAIJ_SeqSBAIJ));
4755   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqbaij_C", MatConvert_SeqAIJ_SeqBAIJ));
4756   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijperm_C", MatConvert_SeqAIJ_SeqAIJPERM));
4757   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijsell_C", MatConvert_SeqAIJ_SeqAIJSELL));
4758 #if defined(PETSC_HAVE_MKL_SPARSE)
4759   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijmkl_C", MatConvert_SeqAIJ_SeqAIJMKL));
4760 #endif
4761 #if defined(PETSC_HAVE_CUDA)
4762   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijcusparse_C", MatConvert_SeqAIJ_SeqAIJCUSPARSE));
4763   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqaijcusparse_seqaij_C", MatProductSetFromOptions_SeqAIJ));
4764   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqaij_seqaijcusparse_C", MatProductSetFromOptions_SeqAIJ));
4765 #endif
4766 #if defined(PETSC_HAVE_KOKKOS_KERNELS)
4767   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijkokkos_C", MatConvert_SeqAIJ_SeqAIJKokkos));
4768 #endif
4769   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijcrl_C", MatConvert_SeqAIJ_SeqAIJCRL));
4770 #if defined(PETSC_HAVE_ELEMENTAL)
4771   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_elemental_C", MatConvert_SeqAIJ_Elemental));
4772 #endif
4773 #if defined(PETSC_HAVE_SCALAPACK)
4774   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_scalapack_C", MatConvert_AIJ_ScaLAPACK));
4775 #endif
4776 #if defined(PETSC_HAVE_HYPRE)
4777   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_hypre_C", MatConvert_AIJ_HYPRE));
4778   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_transpose_seqaij_seqaij_C", MatProductSetFromOptions_Transpose_AIJ_AIJ));
4779 #endif
4780   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqdense_C", MatConvert_SeqAIJ_SeqDense));
4781   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqsell_C", MatConvert_SeqAIJ_SeqSELL));
4782   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_is_C", MatConvert_XAIJ_IS));
4783   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatIsTranspose_C", MatIsTranspose_SeqAIJ));
4784   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatIsHermitianTranspose_C", MatIsTranspose_SeqAIJ));
4785   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqAIJSetPreallocation_C", MatSeqAIJSetPreallocation_SeqAIJ));
4786   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatResetPreallocation_C", MatResetPreallocation_SeqAIJ));
4787   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqAIJSetPreallocationCSR_C", MatSeqAIJSetPreallocationCSR_SeqAIJ));
4788   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatReorderForNonzeroDiagonal_C", MatReorderForNonzeroDiagonal_SeqAIJ));
4789   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_is_seqaij_C", MatProductSetFromOptions_IS_XAIJ));
4790   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqdense_seqaij_C", MatProductSetFromOptions_SeqDense_SeqAIJ));
4791   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqaij_seqaij_C", MatProductSetFromOptions_SeqAIJ));
4792   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqAIJKron_C", MatSeqAIJKron_SeqAIJ));
4793   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSetPreallocationCOO_C", MatSetPreallocationCOO_SeqAIJ));
4794   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSetValuesCOO_C", MatSetValuesCOO_SeqAIJ));
4795   PetscCall(MatCreate_SeqAIJ_Inode(B));
4796   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATSEQAIJ));
4797   PetscCall(MatSeqAIJSetTypeFromOptions(B)); /* this allows changing the matrix subtype to say MATSEQAIJPERM */
4798   PetscFunctionReturn(0);
4799 }
4800 
4801 /*
4802     Given a matrix generated with MatGetFactor() duplicates all the information in A into C
4803 */
4804 PetscErrorCode MatDuplicateNoCreate_SeqAIJ(Mat C, Mat A, MatDuplicateOption cpvalues, PetscBool mallocmatspace)
4805 {
4806   Mat_SeqAIJ *c = (Mat_SeqAIJ *)C->data, *a = (Mat_SeqAIJ *)A->data;
4807   PetscInt    m = A->rmap->n, i;
4808 
4809   PetscFunctionBegin;
4810   PetscCheck(A->assembled || cpvalues == MAT_DO_NOT_COPY_VALUES, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot duplicate unassembled matrix");
4811 
4812   C->factortype = A->factortype;
4813   c->row        = NULL;
4814   c->col        = NULL;
4815   c->icol       = NULL;
4816   c->reallocs   = 0;
4817 
4818   C->assembled    = A->assembled;
4819   C->preallocated = A->preallocated;
4820 
4821   if (A->preallocated) {
4822     PetscCall(PetscLayoutReference(A->rmap, &C->rmap));
4823     PetscCall(PetscLayoutReference(A->cmap, &C->cmap));
4824 
4825     PetscCall(PetscMalloc1(m, &c->imax));
4826     PetscCall(PetscMemcpy(c->imax, a->imax, m * sizeof(PetscInt)));
4827     PetscCall(PetscMalloc1(m, &c->ilen));
4828     PetscCall(PetscMemcpy(c->ilen, a->ilen, m * sizeof(PetscInt)));
4829 
4830     /* allocate the matrix space */
4831     if (mallocmatspace) {
4832       PetscCall(PetscMalloc3(a->i[m], &c->a, a->i[m], &c->j, m + 1, &c->i));
4833 
4834       c->singlemalloc = PETSC_TRUE;
4835 
4836       PetscCall(PetscArraycpy(c->i, a->i, m + 1));
4837       if (m > 0) {
4838         PetscCall(PetscArraycpy(c->j, a->j, a->i[m]));
4839         if (cpvalues == MAT_COPY_VALUES) {
4840           const PetscScalar *aa;
4841 
4842           PetscCall(MatSeqAIJGetArrayRead(A, &aa));
4843           PetscCall(PetscArraycpy(c->a, aa, a->i[m]));
4844           PetscCall(MatSeqAIJGetArrayRead(A, &aa));
4845         } else {
4846           PetscCall(PetscArrayzero(c->a, a->i[m]));
4847         }
4848       }
4849     }
4850 
4851     c->ignorezeroentries = a->ignorezeroentries;
4852     c->roworiented       = a->roworiented;
4853     c->nonew             = a->nonew;
4854     if (a->diag) {
4855       PetscCall(PetscMalloc1(m + 1, &c->diag));
4856       PetscCall(PetscMemcpy(c->diag, a->diag, m * sizeof(PetscInt)));
4857     } else c->diag = NULL;
4858 
4859     c->solve_work         = NULL;
4860     c->saved_values       = NULL;
4861     c->idiag              = NULL;
4862     c->ssor_work          = NULL;
4863     c->keepnonzeropattern = a->keepnonzeropattern;
4864     c->free_a             = PETSC_TRUE;
4865     c->free_ij            = PETSC_TRUE;
4866 
4867     c->rmax  = a->rmax;
4868     c->nz    = a->nz;
4869     c->maxnz = a->nz; /* Since we allocate exactly the right amount */
4870 
4871     c->compressedrow.use   = a->compressedrow.use;
4872     c->compressedrow.nrows = a->compressedrow.nrows;
4873     if (a->compressedrow.use) {
4874       i = a->compressedrow.nrows;
4875       PetscCall(PetscMalloc2(i + 1, &c->compressedrow.i, i, &c->compressedrow.rindex));
4876       PetscCall(PetscArraycpy(c->compressedrow.i, a->compressedrow.i, i + 1));
4877       PetscCall(PetscArraycpy(c->compressedrow.rindex, a->compressedrow.rindex, i));
4878     } else {
4879       c->compressedrow.use    = PETSC_FALSE;
4880       c->compressedrow.i      = NULL;
4881       c->compressedrow.rindex = NULL;
4882     }
4883     c->nonzerorowcnt = a->nonzerorowcnt;
4884     C->nonzerostate  = A->nonzerostate;
4885 
4886     PetscCall(MatDuplicate_SeqAIJ_Inode(A, cpvalues, &C));
4887   }
4888   PetscCall(PetscFunctionListDuplicate(((PetscObject)A)->qlist, &((PetscObject)C)->qlist));
4889   PetscFunctionReturn(0);
4890 }
4891 
4892 PetscErrorCode MatDuplicate_SeqAIJ(Mat A, MatDuplicateOption cpvalues, Mat *B)
4893 {
4894   PetscFunctionBegin;
4895   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
4896   PetscCall(MatSetSizes(*B, A->rmap->n, A->cmap->n, A->rmap->n, A->cmap->n));
4897   if (!(A->rmap->n % A->rmap->bs) && !(A->cmap->n % A->cmap->bs)) PetscCall(MatSetBlockSizesFromMats(*B, A, A));
4898   PetscCall(MatSetType(*B, ((PetscObject)A)->type_name));
4899   PetscCall(MatDuplicateNoCreate_SeqAIJ(*B, A, cpvalues, PETSC_TRUE));
4900   PetscFunctionReturn(0);
4901 }
4902 
4903 PetscErrorCode MatLoad_SeqAIJ(Mat newMat, PetscViewer viewer)
4904 {
4905   PetscBool isbinary, ishdf5;
4906 
4907   PetscFunctionBegin;
4908   PetscValidHeaderSpecific(newMat, MAT_CLASSID, 1);
4909   PetscValidHeaderSpecific(viewer, PETSC_VIEWER_CLASSID, 2);
4910   /* force binary viewer to load .info file if it has not yet done so */
4911   PetscCall(PetscViewerSetUp(viewer));
4912   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
4913   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
4914   if (isbinary) {
4915     PetscCall(MatLoad_SeqAIJ_Binary(newMat, viewer));
4916   } else if (ishdf5) {
4917 #if defined(PETSC_HAVE_HDF5)
4918     PetscCall(MatLoad_AIJ_HDF5(newMat, viewer));
4919 #else
4920     SETERRQ(PetscObjectComm((PetscObject)newMat), PETSC_ERR_SUP, "HDF5 not supported in this build.\nPlease reconfigure using --download-hdf5");
4921 #endif
4922   } else {
4923     SETERRQ(PetscObjectComm((PetscObject)newMat), PETSC_ERR_SUP, "Viewer type %s not yet supported for reading %s matrices", ((PetscObject)viewer)->type_name, ((PetscObject)newMat)->type_name);
4924   }
4925   PetscFunctionReturn(0);
4926 }
4927 
4928 PetscErrorCode MatLoad_SeqAIJ_Binary(Mat mat, PetscViewer viewer)
4929 {
4930   Mat_SeqAIJ *a = (Mat_SeqAIJ *)mat->data;
4931   PetscInt    header[4], *rowlens, M, N, nz, sum, rows, cols, i;
4932 
4933   PetscFunctionBegin;
4934   PetscCall(PetscViewerSetUp(viewer));
4935 
4936   /* read in matrix header */
4937   PetscCall(PetscViewerBinaryRead(viewer, header, 4, NULL, PETSC_INT));
4938   PetscCheck(header[0] == MAT_FILE_CLASSID, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Not a matrix object in file");
4939   M  = header[1];
4940   N  = header[2];
4941   nz = header[3];
4942   PetscCheck(M >= 0, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Matrix row size (%" PetscInt_FMT ") in file is negative", M);
4943   PetscCheck(N >= 0, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Matrix column size (%" PetscInt_FMT ") in file is negative", N);
4944   PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix stored in special format on disk, cannot load as SeqAIJ");
4945 
4946   /* set block sizes from the viewer's .info file */
4947   PetscCall(MatLoad_Binary_BlockSizes(mat, viewer));
4948   /* set local and global sizes if not set already */
4949   if (mat->rmap->n < 0) mat->rmap->n = M;
4950   if (mat->cmap->n < 0) mat->cmap->n = N;
4951   if (mat->rmap->N < 0) mat->rmap->N = M;
4952   if (mat->cmap->N < 0) mat->cmap->N = N;
4953   PetscCall(PetscLayoutSetUp(mat->rmap));
4954   PetscCall(PetscLayoutSetUp(mat->cmap));
4955 
4956   /* check if the matrix sizes are correct */
4957   PetscCall(MatGetSize(mat, &rows, &cols));
4958   PetscCheck(M == rows && N == cols, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix in file of different sizes (%" PetscInt_FMT ", %" PetscInt_FMT ") than the input matrix (%" PetscInt_FMT ", %" PetscInt_FMT ")", M, N, rows, cols);
4959 
4960   /* read in row lengths */
4961   PetscCall(PetscMalloc1(M, &rowlens));
4962   PetscCall(PetscViewerBinaryRead(viewer, rowlens, M, NULL, PETSC_INT));
4963   /* check if sum(rowlens) is same as nz */
4964   sum = 0;
4965   for (i = 0; i < M; i++) sum += rowlens[i];
4966   PetscCheck(sum == nz, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Inconsistent matrix data in file: nonzeros = %" PetscInt_FMT ", sum-row-lengths = %" PetscInt_FMT, nz, sum);
4967   /* preallocate and check sizes */
4968   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(mat, 0, rowlens));
4969   PetscCall(MatGetSize(mat, &rows, &cols));
4970   PetscCheck(M == rows && N == cols, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix in file of different length (%" PetscInt_FMT ", %" PetscInt_FMT ") than the input matrix (%" PetscInt_FMT ", %" PetscInt_FMT ")", M, N, rows, cols);
4971   /* store row lengths */
4972   PetscCall(PetscArraycpy(a->ilen, rowlens, M));
4973   PetscCall(PetscFree(rowlens));
4974 
4975   /* fill in "i" row pointers */
4976   a->i[0] = 0;
4977   for (i = 0; i < M; i++) a->i[i + 1] = a->i[i] + a->ilen[i];
4978   /* read in "j" column indices */
4979   PetscCall(PetscViewerBinaryRead(viewer, a->j, nz, NULL, PETSC_INT));
4980   /* read in "a" nonzero values */
4981   PetscCall(PetscViewerBinaryRead(viewer, a->a, nz, NULL, PETSC_SCALAR));
4982 
4983   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
4984   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));
4985   PetscFunctionReturn(0);
4986 }
4987 
4988 PetscErrorCode MatEqual_SeqAIJ(Mat A, Mat B, PetscBool *flg)
4989 {
4990   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data, *b = (Mat_SeqAIJ *)B->data;
4991   const PetscScalar *aa, *ba;
4992 #if defined(PETSC_USE_COMPLEX)
4993   PetscInt k;
4994 #endif
4995 
4996   PetscFunctionBegin;
4997   /* If the  matrix dimensions are not equal,or no of nonzeros */
4998   if ((A->rmap->n != B->rmap->n) || (A->cmap->n != B->cmap->n) || (a->nz != b->nz)) {
4999     *flg = PETSC_FALSE;
5000     PetscFunctionReturn(0);
5001   }
5002 
5003   /* if the a->i are the same */
5004   PetscCall(PetscArraycmp(a->i, b->i, A->rmap->n + 1, flg));
5005   if (!*flg) PetscFunctionReturn(0);
5006 
5007   /* if a->j are the same */
5008   PetscCall(PetscArraycmp(a->j, b->j, a->nz, flg));
5009   if (!*flg) PetscFunctionReturn(0);
5010 
5011   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
5012   PetscCall(MatSeqAIJGetArrayRead(B, &ba));
5013   /* if a->a are the same */
5014 #if defined(PETSC_USE_COMPLEX)
5015   for (k = 0; k < a->nz; k++) {
5016     if (PetscRealPart(aa[k]) != PetscRealPart(ba[k]) || PetscImaginaryPart(aa[k]) != PetscImaginaryPart(ba[k])) {
5017       *flg = PETSC_FALSE;
5018       PetscFunctionReturn(0);
5019     }
5020   }
5021 #else
5022   PetscCall(PetscArraycmp(aa, ba, a->nz, flg));
5023 #endif
5024   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
5025   PetscCall(MatSeqAIJRestoreArrayRead(B, &ba));
5026   PetscFunctionReturn(0);
5027 }
5028 
5029 /*@
5030      MatCreateSeqAIJWithArrays - Creates an sequential `MATSEQAIJ` matrix using matrix elements (in CSR format)
5031               provided by the user.
5032 
5033       Collective
5034 
5035    Input Parameters:
5036 +   comm - must be an MPI communicator of size 1
5037 .   m - number of rows
5038 .   n - number of columns
5039 .   i - row indices; that is i[0] = 0, i[row] = i[row-1] + number of elements in that row of the matrix
5040 .   j - column indices
5041 -   a - matrix values
5042 
5043    Output Parameter:
5044 .   mat - the matrix
5045 
5046    Level: intermediate
5047 
5048    Notes:
5049        The i, j, and a arrays are not copied by this routine, the user must free these arrays
5050     once the matrix is destroyed and not before
5051 
5052        You cannot set new nonzero locations into this matrix, that will generate an error.
5053 
5054        The i and j indices are 0 based
5055 
5056        The format which is used for the sparse matrix input, is equivalent to a
5057     row-major ordering.. i.e for the following matrix, the input data expected is
5058     as shown
5059 
5060 $        1 0 0
5061 $        2 0 3
5062 $        4 5 6
5063 $
5064 $        i =  {0,1,3,6}  [size = nrow+1  = 3+1]
5065 $        j =  {0,0,2,0,1,2}  [size = 6]; values must be sorted for each row
5066 $        v =  {1,2,3,4,5,6}  [size = 6]
5067 
5068 .seealso: `MatCreate()`, `MatCreateAIJ()`, `MatCreateSeqAIJ()`, `MatCreateMPIAIJWithArrays()`, `MatMPIAIJSetPreallocationCSR()`
5069 @*/
5070 PetscErrorCode MatCreateSeqAIJWithArrays(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt i[], PetscInt j[], PetscScalar a[], Mat *mat)
5071 {
5072   PetscInt    ii;
5073   Mat_SeqAIJ *aij;
5074   PetscInt    jj;
5075 
5076   PetscFunctionBegin;
5077   PetscCheck(m <= 0 || i[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "i (row indices) must start with 0");
5078   PetscCall(MatCreate(comm, mat));
5079   PetscCall(MatSetSizes(*mat, m, n, m, n));
5080   /* PetscCall(MatSetBlockSizes(*mat,,)); */
5081   PetscCall(MatSetType(*mat, MATSEQAIJ));
5082   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*mat, MAT_SKIP_ALLOCATION, NULL));
5083   aij = (Mat_SeqAIJ *)(*mat)->data;
5084   PetscCall(PetscMalloc1(m, &aij->imax));
5085   PetscCall(PetscMalloc1(m, &aij->ilen));
5086 
5087   aij->i            = i;
5088   aij->j            = j;
5089   aij->a            = a;
5090   aij->singlemalloc = PETSC_FALSE;
5091   aij->nonew        = -1; /*this indicates that inserting a new value in the matrix that generates a new nonzero is an error*/
5092   aij->free_a       = PETSC_FALSE;
5093   aij->free_ij      = PETSC_FALSE;
5094 
5095   for (ii = 0, aij->nonzerorowcnt = 0, aij->rmax = 0; ii < m; ii++) {
5096     aij->ilen[ii] = aij->imax[ii] = i[ii + 1] - i[ii];
5097     if (PetscDefined(USE_DEBUG)) {
5098       PetscCheck(i[ii + 1] - i[ii] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Negative row length in i (row indices) row = %" PetscInt_FMT " length = %" PetscInt_FMT, ii, i[ii + 1] - i[ii]);
5099       for (jj = i[ii] + 1; jj < i[ii + 1]; jj++) {
5100         PetscCheck(j[jj] >= j[jj - 1], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column entry number %" PetscInt_FMT " (actual column %" PetscInt_FMT ") in row %" PetscInt_FMT " is not sorted", jj - i[ii], j[jj], ii);
5101         PetscCheck(j[jj] != j[jj - 1], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column entry number %" PetscInt_FMT " (actual column %" PetscInt_FMT ") in row %" PetscInt_FMT " is identical to previous entry", jj - i[ii], j[jj], ii);
5102       }
5103     }
5104   }
5105   if (PetscDefined(USE_DEBUG)) {
5106     for (ii = 0; ii < aij->i[m]; ii++) {
5107       PetscCheck(j[ii] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Negative column index at location = %" PetscInt_FMT " index = %" PetscInt_FMT, ii, j[ii]);
5108       PetscCheck(j[ii] <= n - 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column index to large at location = %" PetscInt_FMT " index = %" PetscInt_FMT, ii, j[ii]);
5109     }
5110   }
5111 
5112   PetscCall(MatAssemblyBegin(*mat, MAT_FINAL_ASSEMBLY));
5113   PetscCall(MatAssemblyEnd(*mat, MAT_FINAL_ASSEMBLY));
5114   PetscFunctionReturn(0);
5115 }
5116 
5117 /*@
5118      MatCreateSeqAIJFromTriple - Creates an sequential `MATSEQAIJ` matrix using matrix elements (in COO format)
5119               provided by the user.
5120 
5121       Collective
5122 
5123    Input Parameters:
5124 +   comm - must be an MPI communicator of size 1
5125 .   m   - number of rows
5126 .   n   - number of columns
5127 .   i   - row indices
5128 .   j   - column indices
5129 .   a   - matrix values
5130 .   nz  - number of nonzeros
5131 -   idx - if the i and j indices start with 1 use `PETSC_TRUE` otherwise use `PETSC_FALSE`
5132 
5133    Output Parameter:
5134 .   mat - the matrix
5135 
5136    Level: intermediate
5137 
5138    Example:
5139        For the following matrix, the input data expected is as shown (using 0 based indexing)
5140 .vb
5141         1 0 0
5142         2 0 3
5143         4 5 6
5144 
5145         i =  {0,1,1,2,2,2}
5146         j =  {0,0,2,0,1,2}
5147         v =  {1,2,3,4,5,6}
5148 .ve
5149 
5150 .seealso: `MatCreate()`, `MatCreateAIJ()`, `MatCreateSeqAIJ()`, `MatCreateSeqAIJWithArrays()`, `MatMPIAIJSetPreallocationCSR()`, `MatSetValuesCOO()`
5151 @*/
5152 PetscErrorCode MatCreateSeqAIJFromTriple(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt i[], PetscInt j[], PetscScalar a[], Mat *mat, PetscInt nz, PetscBool idx)
5153 {
5154   PetscInt ii, *nnz, one = 1, row, col;
5155 
5156   PetscFunctionBegin;
5157   PetscCall(PetscCalloc1(m, &nnz));
5158   for (ii = 0; ii < nz; ii++) nnz[i[ii] - !!idx] += 1;
5159   PetscCall(MatCreate(comm, mat));
5160   PetscCall(MatSetSizes(*mat, m, n, m, n));
5161   PetscCall(MatSetType(*mat, MATSEQAIJ));
5162   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*mat, 0, nnz));
5163   for (ii = 0; ii < nz; ii++) {
5164     if (idx) {
5165       row = i[ii] - 1;
5166       col = j[ii] - 1;
5167     } else {
5168       row = i[ii];
5169       col = j[ii];
5170     }
5171     PetscCall(MatSetValues(*mat, one, &row, one, &col, &a[ii], ADD_VALUES));
5172   }
5173   PetscCall(MatAssemblyBegin(*mat, MAT_FINAL_ASSEMBLY));
5174   PetscCall(MatAssemblyEnd(*mat, MAT_FINAL_ASSEMBLY));
5175   PetscCall(PetscFree(nnz));
5176   PetscFunctionReturn(0);
5177 }
5178 
5179 PetscErrorCode MatSeqAIJInvalidateDiagonal(Mat A)
5180 {
5181   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
5182 
5183   PetscFunctionBegin;
5184   a->idiagvalid  = PETSC_FALSE;
5185   a->ibdiagvalid = PETSC_FALSE;
5186 
5187   PetscCall(MatSeqAIJInvalidateDiagonal_Inode(A));
5188   PetscFunctionReturn(0);
5189 }
5190 
5191 PetscErrorCode MatCreateMPIMatConcatenateSeqMat_SeqAIJ(MPI_Comm comm, Mat inmat, PetscInt n, MatReuse scall, Mat *outmat)
5192 {
5193   PetscFunctionBegin;
5194   PetscCall(MatCreateMPIMatConcatenateSeqMat_MPIAIJ(comm, inmat, n, scall, outmat));
5195   PetscFunctionReturn(0);
5196 }
5197 
5198 /*
5199  Permute A into C's *local* index space using rowemb,colemb.
5200  The embedding are supposed to be injections and the above implies that the range of rowemb is a subset
5201  of [0,m), colemb is in [0,n).
5202  If pattern == DIFFERENT_NONZERO_PATTERN, C is preallocated according to A.
5203  */
5204 PetscErrorCode MatSetSeqMat_SeqAIJ(Mat C, IS rowemb, IS colemb, MatStructure pattern, Mat B)
5205 {
5206   /* If making this function public, change the error returned in this function away from _PLIB. */
5207   Mat_SeqAIJ     *Baij;
5208   PetscBool       seqaij;
5209   PetscInt        m, n, *nz, i, j, count;
5210   PetscScalar     v;
5211   const PetscInt *rowindices, *colindices;
5212 
5213   PetscFunctionBegin;
5214   if (!B) PetscFunctionReturn(0);
5215   /* Check to make sure the target matrix (and embeddings) are compatible with C and each other. */
5216   PetscCall(PetscObjectBaseTypeCompare((PetscObject)B, MATSEQAIJ, &seqaij));
5217   PetscCheck(seqaij, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Input matrix is of wrong type");
5218   if (rowemb) {
5219     PetscCall(ISGetLocalSize(rowemb, &m));
5220     PetscCheck(m == B->rmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Row IS of size %" PetscInt_FMT " is incompatible with matrix row size %" PetscInt_FMT, m, B->rmap->n);
5221   } else {
5222     PetscCheck(C->rmap->n == B->rmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Input matrix is row-incompatible with the target matrix");
5223   }
5224   if (colemb) {
5225     PetscCall(ISGetLocalSize(colemb, &n));
5226     PetscCheck(n == B->cmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Diag col IS of size %" PetscInt_FMT " is incompatible with input matrix col size %" PetscInt_FMT, n, B->cmap->n);
5227   } else {
5228     PetscCheck(C->cmap->n == B->cmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Input matrix is col-incompatible with the target matrix");
5229   }
5230 
5231   Baij = (Mat_SeqAIJ *)(B->data);
5232   if (pattern == DIFFERENT_NONZERO_PATTERN) {
5233     PetscCall(PetscMalloc1(B->rmap->n, &nz));
5234     for (i = 0; i < B->rmap->n; i++) nz[i] = Baij->i[i + 1] - Baij->i[i];
5235     PetscCall(MatSeqAIJSetPreallocation(C, 0, nz));
5236     PetscCall(PetscFree(nz));
5237   }
5238   if (pattern == SUBSET_NONZERO_PATTERN) PetscCall(MatZeroEntries(C));
5239   count      = 0;
5240   rowindices = NULL;
5241   colindices = NULL;
5242   if (rowemb) PetscCall(ISGetIndices(rowemb, &rowindices));
5243   if (colemb) PetscCall(ISGetIndices(colemb, &colindices));
5244   for (i = 0; i < B->rmap->n; i++) {
5245     PetscInt row;
5246     row = i;
5247     if (rowindices) row = rowindices[i];
5248     for (j = Baij->i[i]; j < Baij->i[i + 1]; j++) {
5249       PetscInt col;
5250       col = Baij->j[count];
5251       if (colindices) col = colindices[col];
5252       v = Baij->a[count];
5253       PetscCall(MatSetValues(C, 1, &row, 1, &col, &v, INSERT_VALUES));
5254       ++count;
5255     }
5256   }
5257   /* FIXME: set C's nonzerostate correctly. */
5258   /* Assembly for C is necessary. */
5259   C->preallocated  = PETSC_TRUE;
5260   C->assembled     = PETSC_TRUE;
5261   C->was_assembled = PETSC_FALSE;
5262   PetscFunctionReturn(0);
5263 }
5264 
5265 PetscFunctionList MatSeqAIJList = NULL;
5266 
5267 /*@C
5268    MatSeqAIJSetType - Converts a `MATSEQAIJ` matrix to a subtype
5269 
5270    Collective on mat
5271 
5272    Input Parameters:
5273 +  mat      - the matrix object
5274 -  matype   - matrix type
5275 
5276    Options Database Key:
5277 .  -mat_seqai_type  <method> - for example seqaijcrl
5278 
5279   Level: intermediate
5280 
5281 .seealso: `PCSetType()`, `VecSetType()`, `MatCreate()`, `MatType`, `Mat`
5282 @*/
5283 PetscErrorCode MatSeqAIJSetType(Mat mat, MatType matype)
5284 {
5285   PetscBool sametype;
5286   PetscErrorCode (*r)(Mat, MatType, MatReuse, Mat *);
5287 
5288   PetscFunctionBegin;
5289   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
5290   PetscCall(PetscObjectTypeCompare((PetscObject)mat, matype, &sametype));
5291   if (sametype) PetscFunctionReturn(0);
5292 
5293   PetscCall(PetscFunctionListFind(MatSeqAIJList, matype, &r));
5294   PetscCheck(r, PETSC_COMM_SELF, PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown Mat type given: %s", matype);
5295   PetscCall((*r)(mat, matype, MAT_INPLACE_MATRIX, &mat));
5296   PetscFunctionReturn(0);
5297 }
5298 
5299 /*@C
5300   MatSeqAIJRegister -  - Adds a new sub-matrix type for sequential `MATSEQAIJ` matrices
5301 
5302    Not Collective
5303 
5304    Input Parameters:
5305 +  name - name of a new user-defined matrix type, for example `MATSEQAIJCRL`
5306 -  function - routine to convert to subtype
5307 
5308    Notes:
5309    `MatSeqAIJRegister()` may be called multiple times to add several user-defined solvers.
5310 
5311    Then, your matrix can be chosen with the procedural interface at runtime via the option
5312 $     -mat_seqaij_type my_mat
5313 
5314    Level: advanced
5315 
5316 .seealso: `MatSeqAIJRegisterAll()`
5317 @*/
5318 PetscErrorCode MatSeqAIJRegister(const char sname[], PetscErrorCode (*function)(Mat, MatType, MatReuse, Mat *))
5319 {
5320   PetscFunctionBegin;
5321   PetscCall(MatInitializePackage());
5322   PetscCall(PetscFunctionListAdd(&MatSeqAIJList, sname, function));
5323   PetscFunctionReturn(0);
5324 }
5325 
5326 PetscBool MatSeqAIJRegisterAllCalled = PETSC_FALSE;
5327 
5328 /*@C
5329   MatSeqAIJRegisterAll - Registers all of the matrix subtypes of `MATSSEQAIJ`
5330 
5331   Not Collective
5332 
5333   Level: advanced
5334 
5335 .seealso: `MatRegisterAll()`, `MatSeqAIJRegister()`
5336 @*/
5337 PetscErrorCode MatSeqAIJRegisterAll(void)
5338 {
5339   PetscFunctionBegin;
5340   if (MatSeqAIJRegisterAllCalled) PetscFunctionReturn(0);
5341   MatSeqAIJRegisterAllCalled = PETSC_TRUE;
5342 
5343   PetscCall(MatSeqAIJRegister(MATSEQAIJCRL, MatConvert_SeqAIJ_SeqAIJCRL));
5344   PetscCall(MatSeqAIJRegister(MATSEQAIJPERM, MatConvert_SeqAIJ_SeqAIJPERM));
5345   PetscCall(MatSeqAIJRegister(MATSEQAIJSELL, MatConvert_SeqAIJ_SeqAIJSELL));
5346 #if defined(PETSC_HAVE_MKL_SPARSE)
5347   PetscCall(MatSeqAIJRegister(MATSEQAIJMKL, MatConvert_SeqAIJ_SeqAIJMKL));
5348 #endif
5349 #if defined(PETSC_HAVE_CUDA)
5350   PetscCall(MatSeqAIJRegister(MATSEQAIJCUSPARSE, MatConvert_SeqAIJ_SeqAIJCUSPARSE));
5351 #endif
5352 #if defined(PETSC_HAVE_KOKKOS_KERNELS)
5353   PetscCall(MatSeqAIJRegister(MATSEQAIJKOKKOS, MatConvert_SeqAIJ_SeqAIJKokkos));
5354 #endif
5355 #if defined(PETSC_HAVE_VIENNACL) && defined(PETSC_HAVE_VIENNACL_NO_CUDA)
5356   PetscCall(MatSeqAIJRegister(MATMPIAIJVIENNACL, MatConvert_SeqAIJ_SeqAIJViennaCL));
5357 #endif
5358   PetscFunctionReturn(0);
5359 }
5360 
5361 /*
5362     Special version for direct calls from Fortran
5363 */
5364 #include <petsc/private/fortranimpl.h>
5365 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5366   #define matsetvaluesseqaij_ MATSETVALUESSEQAIJ
5367 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5368   #define matsetvaluesseqaij_ matsetvaluesseqaij
5369 #endif
5370 
5371 /* Change these macros so can be used in void function */
5372 
5373 /* Change these macros so can be used in void function */
5374 /* Identical to PetscCallVoid, except it assigns to *_ierr */
5375 #undef PetscCall
5376 #define PetscCall(...) \
5377   do { \
5378     PetscErrorCode ierr_msv_mpiaij = __VA_ARGS__; \
5379     if (PetscUnlikely(ierr_msv_mpiaij)) { \
5380       *_ierr = PetscError(PETSC_COMM_SELF, __LINE__, PETSC_FUNCTION_NAME, __FILE__, ierr_msv_mpiaij, PETSC_ERROR_REPEAT, " "); \
5381       return; \
5382     } \
5383   } while (0)
5384 
5385 #undef SETERRQ
5386 #define SETERRQ(comm, ierr, ...) \
5387   do { \
5388     *_ierr = PetscError(comm, __LINE__, PETSC_FUNCTION_NAME, __FILE__, ierr, PETSC_ERROR_INITIAL, __VA_ARGS__); \
5389     return; \
5390   } while (0)
5391 
5392 PETSC_EXTERN void matsetvaluesseqaij_(Mat *AA, PetscInt *mm, const PetscInt im[], PetscInt *nn, const PetscInt in[], const PetscScalar v[], InsertMode *isis, PetscErrorCode *_ierr)
5393 {
5394   Mat         A = *AA;
5395   PetscInt    m = *mm, n = *nn;
5396   InsertMode  is = *isis;
5397   Mat_SeqAIJ *a  = (Mat_SeqAIJ *)A->data;
5398   PetscInt   *rp, k, low, high, t, ii, row, nrow, i, col, l, rmax, N;
5399   PetscInt   *imax, *ai, *ailen;
5400   PetscInt   *aj, nonew = a->nonew, lastcol = -1;
5401   MatScalar  *ap, value, *aa;
5402   PetscBool   ignorezeroentries = a->ignorezeroentries;
5403   PetscBool   roworiented       = a->roworiented;
5404 
5405   PetscFunctionBegin;
5406   MatCheckPreallocated(A, 1);
5407   imax  = a->imax;
5408   ai    = a->i;
5409   ailen = a->ilen;
5410   aj    = a->j;
5411   aa    = a->a;
5412 
5413   for (k = 0; k < m; k++) { /* loop over added rows */
5414     row = im[k];
5415     if (row < 0) continue;
5416     PetscCheck(row < A->rmap->n, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Row too large");
5417     rp   = aj + ai[row];
5418     ap   = aa + ai[row];
5419     rmax = imax[row];
5420     nrow = ailen[row];
5421     low  = 0;
5422     high = nrow;
5423     for (l = 0; l < n; l++) { /* loop over added columns */
5424       if (in[l] < 0) continue;
5425       PetscCheck(in[l] < A->cmap->n, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Column too large");
5426       col = in[l];
5427       if (roworiented) value = v[l + k * n];
5428       else value = v[k + l * m];
5429 
5430       if (value == 0.0 && ignorezeroentries && (is == ADD_VALUES)) continue;
5431 
5432       if (col <= lastcol) low = 0;
5433       else high = nrow;
5434       lastcol = col;
5435       while (high - low > 5) {
5436         t = (low + high) / 2;
5437         if (rp[t] > col) high = t;
5438         else low = t;
5439       }
5440       for (i = low; i < high; i++) {
5441         if (rp[i] > col) break;
5442         if (rp[i] == col) {
5443           if (is == ADD_VALUES) ap[i] += value;
5444           else ap[i] = value;
5445           goto noinsert;
5446         }
5447       }
5448       if (value == 0.0 && ignorezeroentries) goto noinsert;
5449       if (nonew == 1) goto noinsert;
5450       PetscCheck(nonew != -1, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new nonzero in the matrix");
5451       MatSeqXAIJReallocateAIJ(A, A->rmap->n, 1, nrow, row, col, rmax, aa, ai, aj, rp, ap, imax, nonew, MatScalar);
5452       N = nrow++ - 1;
5453       a->nz++;
5454       high++;
5455       /* shift up all the later entries in this row */
5456       for (ii = N; ii >= i; ii--) {
5457         rp[ii + 1] = rp[ii];
5458         ap[ii + 1] = ap[ii];
5459       }
5460       rp[i] = col;
5461       ap[i] = value;
5462       A->nonzerostate++;
5463     noinsert:;
5464       low = i + 1;
5465     }
5466     ailen[row] = nrow;
5467   }
5468   PetscFunctionReturnVoid();
5469 }
5470 /* Undefining these here since they were redefined from their original definition above! No
5471  * other PETSc functions should be defined past this point, as it is impossible to recover the
5472  * original definitions */
5473 #undef PetscCall
5474 #undef SETERRQ
5475