xref: /petsc/src/mat/utils/axpy.c (revision ce94432eddcd14845bc7e8083b7f8ea723b9bf7d)
1 
2 #include <petsc-private/matimpl.h>  /*I   "petscmat.h"  I*/
3 
4 #undef __FUNCT__
5 #define __FUNCT__ "MatAXPY"
6 /*@
7    MatAXPY - Computes Y = a*X + Y.
8 
9    Logically  Collective on Mat
10 
11    Input Parameters:
12 +  a - the scalar multiplier
13 .  X - the first matrix
14 .  Y - the second matrix
15 -  str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN
16          or SUBSET_NONZERO_PATTERN (nonzeros of X is a subset of Y's)
17 
18    Level: intermediate
19 
20 .keywords: matrix, add
21 
22 .seealso: MatAYPX()
23  @*/
24 PetscErrorCode  MatAXPY(Mat Y,PetscScalar a,Mat X,MatStructure str)
25 {
26   PetscErrorCode ierr;
27   PetscInt       m1,m2,n1,n2;
28 
29   PetscFunctionBegin;
30   PetscValidHeaderSpecific(X,MAT_CLASSID,3);
31   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
32   PetscValidLogicalCollectiveScalar(Y,a,2);
33   ierr = MatGetSize(X,&m1,&n1);CHKERRQ(ierr);
34   ierr = MatGetSize(Y,&m2,&n2);CHKERRQ(ierr);
35   if (m1 != m2 || n1 != n2) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Non conforming matrix add: %D %D %D %D",m1,m2,n1,n2);
36 
37   ierr = PetscLogEventBegin(MAT_AXPY,Y,0,0,0);CHKERRQ(ierr);
38   if (Y->ops->axpy) {
39     ierr = (*Y->ops->axpy)(Y,a,X,str);CHKERRQ(ierr);
40   } else {
41     ierr = MatAXPY_Basic(Y,a,X,str);CHKERRQ(ierr);
42   }
43   ierr = PetscLogEventEnd(MAT_AXPY,Y,0,0,0);CHKERRQ(ierr);
44 #if defined(PETSC_HAVE_CUSP)
45   if (Y->valid_GPU_matrix != PETSC_CUSP_UNALLOCATED) {
46     Y->valid_GPU_matrix = PETSC_CUSP_CPU;
47   }
48 #endif
49   PetscFunctionReturn(0);
50 }
51 
52 #undef __FUNCT__
53 #define __FUNCT__ "MatAXPY_Basic"
54 PetscErrorCode MatAXPY_Basic(Mat Y,PetscScalar a,Mat X,MatStructure str)
55 {
56   PetscInt          i,start,end,j,ncols,m,n;
57   PetscErrorCode    ierr;
58   const PetscInt    *row;
59   PetscScalar       *val;
60   const PetscScalar *vals;
61 
62   PetscFunctionBegin;
63   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
64   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
65   if (a == 1.0) {
66     for (i = start; i < end; i++) {
67       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
68       ierr = MatSetValues(Y,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
69       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
70     }
71   } else {
72     ierr = PetscMalloc((n+1)*sizeof(PetscScalar),&val);CHKERRQ(ierr);
73     for (i=start; i<end; i++) {
74       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
75       for (j=0; j<ncols; j++) {
76         val[j] = a*vals[j];
77       }
78       ierr = MatSetValues(Y,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
79       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
80     }
81     ierr = PetscFree(val);CHKERRQ(ierr);
82   }
83   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
84   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
85   PetscFunctionReturn(0);
86 }
87 
88 #undef __FUNCT__
89 #define __FUNCT__ "MatAXPY_BasicWithPreallocation"
90 PetscErrorCode MatAXPY_BasicWithPreallocation(Mat B,Mat Y,PetscScalar a,Mat X,MatStructure str)
91 {
92   PetscInt          i,start,end,j,ncols,m,n;
93   PetscErrorCode    ierr;
94   const PetscInt    *row;
95   PetscScalar       *val;
96   const PetscScalar *vals;
97 
98   PetscFunctionBegin;
99   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
100   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
101   if (a == 1.0) {
102     for (i = start; i < end; i++) {
103       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
104       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
105       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
106 
107       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
108       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
109       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
110     }
111   } else {
112     ierr = PetscMalloc((n+1)*sizeof(PetscScalar),&val);CHKERRQ(ierr);
113     for (i=start; i<end; i++) {
114       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
115       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
116       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
117 
118       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
119       for (j=0; j<ncols; j++) {
120         val[j] = a*vals[j];
121       }
122       ierr = MatSetValues(B,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
123       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
124     }
125     ierr = PetscFree(val);CHKERRQ(ierr);
126   }
127   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
128   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
129   PetscFunctionReturn(0);
130 }
131 
132 #undef __FUNCT__
133 #define __FUNCT__ "MatShift"
134 /*@
135    MatShift - Computes Y =  Y + a I, where a is a PetscScalar and I is the identity matrix.
136 
137    Neighbor-wise Collective on Mat
138 
139    Input Parameters:
140 +  Y - the matrices
141 -  a - the PetscScalar
142 
143    Level: intermediate
144 
145 .keywords: matrix, add, shift
146 
147 .seealso: MatDiagonalSet()
148  @*/
149 PetscErrorCode  MatShift(Mat Y,PetscScalar a)
150 {
151   PetscErrorCode ierr;
152   PetscInt       i,start,end;
153 
154   PetscFunctionBegin;
155   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
156   if (!Y->assembled) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
157   if (Y->factortype) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
158   MatCheckPreallocated(Y,1);
159 
160   if (Y->ops->shift) {
161     ierr = (*Y->ops->shift)(Y,a);CHKERRQ(ierr);
162   } else {
163     PetscScalar alpha = a;
164     ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
165     for (i=start; i<end; i++) {
166       ierr = MatSetValues(Y,1,&i,1,&i,&alpha,ADD_VALUES);CHKERRQ(ierr);
167     }
168     ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
169     ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
170   }
171 #if defined(PETSC_HAVE_CUSP)
172   if (Y->valid_GPU_matrix != PETSC_CUSP_UNALLOCATED) {
173     Y->valid_GPU_matrix = PETSC_CUSP_CPU;
174   }
175 #endif
176   PetscFunctionReturn(0);
177 }
178 
179 #undef __FUNCT__
180 #define __FUNCT__ "MatDiagonalSet_Default"
181 PetscErrorCode  MatDiagonalSet_Default(Mat Y,Vec D,InsertMode is)
182 {
183   PetscErrorCode ierr;
184   PetscInt       i,start,end,vstart,vend;
185   PetscScalar    *v;
186 
187   PetscFunctionBegin;
188   ierr = VecGetOwnershipRange(D,&vstart,&vend);CHKERRQ(ierr);
189   ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
190   if (vstart != start || vend != end) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Vector ownership range not compatible with matrix: %D %D vec %D %D mat",vstart,vend,start,end);
191   ierr = VecGetArray(D,&v);CHKERRQ(ierr);
192   for (i=start; i<end; i++) {
193     ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,is);CHKERRQ(ierr);
194   }
195   ierr = VecRestoreArray(D,&v);CHKERRQ(ierr);
196   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
197   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
198   PetscFunctionReturn(0);
199 }
200 
201 #undef __FUNCT__
202 #define __FUNCT__ "MatDiagonalSet"
203 /*@
204    MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
205    that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
206    INSERT_VALUES.
207 
208    Input Parameters:
209 +  Y - the input matrix
210 .  D - the diagonal matrix, represented as a vector
211 -  i - INSERT_VALUES or ADD_VALUES
212 
213    Neighbor-wise Collective on Mat and Vec
214 
215    Level: intermediate
216 
217 .keywords: matrix, add, shift, diagonal
218 
219 .seealso: MatShift()
220 @*/
221 PetscErrorCode  MatDiagonalSet(Mat Y,Vec D,InsertMode is)
222 {
223   PetscErrorCode ierr;
224 
225   PetscFunctionBegin;
226   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
227   PetscValidHeaderSpecific(D,VEC_CLASSID,2);
228   if (Y->ops->diagonalset) {
229     ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
230   } else {
231     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
232   }
233   PetscFunctionReturn(0);
234 }
235 
236 #undef __FUNCT__
237 #define __FUNCT__ "MatAYPX"
238 /*@
239    MatAYPX - Computes Y = a*Y + X.
240 
241    Logically on Mat
242 
243    Input Parameters:
244 +  a - the PetscScalar multiplier
245 .  Y - the first matrix
246 .  X - the second matrix
247 -  str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
248 
249    Level: intermediate
250 
251 .keywords: matrix, add
252 
253 .seealso: MatAXPY()
254  @*/
255 PetscErrorCode  MatAYPX(Mat Y,PetscScalar a,Mat X,MatStructure str)
256 {
257   PetscScalar    one = 1.0;
258   PetscErrorCode ierr;
259   PetscInt       mX,mY,nX,nY;
260 
261   PetscFunctionBegin;
262   PetscValidHeaderSpecific(X,MAT_CLASSID,3);
263   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
264   PetscValidLogicalCollectiveScalar(Y,a,2);
265   ierr = MatGetSize(X,&mX,&nX);CHKERRQ(ierr);
266   ierr = MatGetSize(X,&mY,&nY);CHKERRQ(ierr);
267   if (mX != mY || nX != nY) SETERRQ4(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"Non conforming matrices: %D %D first %D %D second",mX,mY,nX,nY);
268 
269   ierr = MatScale(Y,a);CHKERRQ(ierr);
270   ierr = MatAXPY(Y,one,X,str);CHKERRQ(ierr);
271   PetscFunctionReturn(0);
272 }
273 
274 #undef __FUNCT__
275 #define __FUNCT__ "MatComputeExplicitOperator"
276 /*@
277     MatComputeExplicitOperator - Computes the explicit matrix
278 
279     Collective on Mat
280 
281     Input Parameter:
282 .   inmat - the matrix
283 
284     Output Parameter:
285 .   mat - the explict preconditioned operator
286 
287     Notes:
288     This computation is done by applying the operators to columns of the
289     identity matrix.
290 
291     Currently, this routine uses a dense matrix format when 1 processor
292     is used and a sparse format otherwise.  This routine is costly in general,
293     and is recommended for use only with relatively small systems.
294 
295     Level: advanced
296 
297 .keywords: Mat, compute, explicit, operator
298 @*/
299 PetscErrorCode  MatComputeExplicitOperator(Mat inmat,Mat *mat)
300 {
301   Vec            in,out;
302   PetscErrorCode ierr;
303   PetscInt       i,m,n,M,N,*rows,start,end;
304   MPI_Comm       comm;
305   PetscScalar    *array,zero = 0.0,one = 1.0;
306   PetscMPIInt    size;
307 
308   PetscFunctionBegin;
309   PetscValidHeaderSpecific(inmat,MAT_CLASSID,1);
310   PetscValidPointer(mat,2);
311 
312   ierr = PetscObjectGetComm((PetscObject)inmat,&comm);CHKERRQ(ierr);
313   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
314 
315   ierr = MatGetLocalSize(inmat,&m,&n);CHKERRQ(ierr);
316   ierr = MatGetSize(inmat,&M,&N);CHKERRQ(ierr);
317   ierr = MatGetVecs(inmat,&in,&out);CHKERRQ(ierr);
318   ierr = VecSetOption(in,VEC_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
319   ierr = VecGetOwnershipRange(out,&start,&end);CHKERRQ(ierr);
320   ierr = PetscMalloc(m*sizeof(PetscInt),&rows);CHKERRQ(ierr);
321   for (i=0; i<m; i++) rows[i] = start + i;
322 
323   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
324   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
325   if (size == 1) {
326     ierr = MatSetType(*mat,MATSEQDENSE);CHKERRQ(ierr);
327     ierr = MatSeqDenseSetPreallocation(*mat,NULL);CHKERRQ(ierr);
328   } else {
329     ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
330     ierr = MatMPIAIJSetPreallocation(*mat,n,NULL,N-n,NULL);CHKERRQ(ierr);
331   }
332 
333   for (i=0; i<N; i++) {
334 
335     ierr = VecSet(in,zero);CHKERRQ(ierr);
336     ierr = VecSetValues(in,1,&i,&one,INSERT_VALUES);CHKERRQ(ierr);
337     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
338     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
339 
340     ierr = MatMult(inmat,in,out);CHKERRQ(ierr);
341 
342     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
343     ierr = MatSetValues(*mat,m,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
344     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
345 
346   }
347   ierr = PetscFree(rows);CHKERRQ(ierr);
348   ierr = VecDestroy(&out);CHKERRQ(ierr);
349   ierr = VecDestroy(&in);CHKERRQ(ierr);
350   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
351   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
352   PetscFunctionReturn(0);
353 }
354 
355 /* Get the map xtoy which is used by MatAXPY() in the case of SUBSET_NONZERO_PATTERN */
356 #undef __FUNCT__
357 #define __FUNCT__ "MatAXPYGetxtoy_Private"
358 PetscErrorCode MatAXPYGetxtoy_Private(PetscInt m,PetscInt *xi,PetscInt *xj,PetscInt *xgarray, PetscInt *yi,PetscInt *yj,PetscInt *ygarray, PetscInt **xtoy)
359 {
360   PetscErrorCode ierr;
361   PetscInt       row,i,nz,xcol,ycol,jx,jy,*x2y;
362 
363   PetscFunctionBegin;
364   ierr = PetscMalloc(xi[m]*sizeof(PetscInt),&x2y);CHKERRQ(ierr);
365   i    = 0;
366   for (row=0; row<m; row++) {
367     nz = xi[1] - xi[0];
368     jy = 0;
369     for (jx=0; jx<nz; jx++,jy++) {
370       if (xgarray && ygarray) {
371         xcol = xgarray[xj[*xi + jx]];
372         ycol = ygarray[yj[*yi + jy]];
373       } else {
374         xcol = xj[*xi + jx];
375         ycol = yj[*yi + jy];  /* col index for y */
376       }
377       while (ycol < xcol) {
378         jy++;
379         if (ygarray) {
380           ycol = ygarray[yj[*yi + jy]];
381         } else {
382           ycol = yj[*yi + jy];
383         }
384       }
385       if (xcol != ycol) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"X matrix entry (%D,%D) is not in Y matrix",row,ycol);
386       x2y[i++] = *yi + jy;
387     }
388     xi++; yi++;
389   }
390   *xtoy = x2y;
391   PetscFunctionReturn(0);
392 }
393 
394 #undef __FUNCT__
395 #define __FUNCT__ "MatChop"
396 /*@
397   MatChop - Set all values in the matrix less than the tolerance to zero
398 
399   Input Parameters:
400 + A   - The matrix
401 - tol - The zero tolerance
402 
403   Output Parameters:
404 . A - The chopped matrix
405 
406   Level: intermediate
407 
408 .seealso: MatCreate(), MatZeroEntries()
409  @*/
410 PetscErrorCode MatChop(Mat A, PetscReal tol)
411 {
412   PetscScalar    *newVals;
413   PetscInt       *newCols;
414   PetscInt       rStart, rEnd, numRows, maxRows, r, colMax = 0;
415   PetscErrorCode ierr;
416 
417   PetscFunctionBegin;
418   ierr = MatGetOwnershipRange(A, &rStart, &rEnd);CHKERRQ(ierr);
419   for (r = rStart; r < rEnd; ++r) {
420     PetscInt ncols;
421 
422     ierr   = MatGetRow(A, r, &ncols, NULL, NULL);CHKERRQ(ierr);
423     colMax = PetscMax(colMax, ncols);CHKERRQ(ierr);
424     ierr   = MatRestoreRow(A, r, &ncols, NULL, NULL);CHKERRQ(ierr);
425   }
426   numRows = rEnd - rStart;
427   ierr    = MPI_Allreduce(&numRows, &maxRows, 1, MPIU_INT, MPI_MAX, PETSC_COMM_WORLD);CHKERRQ(ierr);
428   ierr    = PetscMalloc2(colMax,PetscInt,&newCols,colMax,PetscScalar,&newVals);CHKERRQ(ierr);
429   for (r = rStart; r < rStart+maxRows; ++r) {
430     const PetscScalar *vals;
431     const PetscInt    *cols;
432     PetscInt          ncols, c;
433 
434     if (r < rEnd) {
435       ierr = MatGetRow(A, r, &ncols, &cols, &vals);CHKERRQ(ierr);
436       for (c = 0; c < ncols; ++c) {
437         newCols[c] = cols[c];
438         newVals[c] = PetscAbsScalar(vals[c]) < tol ? 0.0 : vals[c];
439       }
440       ierr = MatRestoreRow(A, r, &ncols, &cols, &vals);CHKERRQ(ierr);
441       ierr = MatSetValues(A, 1, &r, ncols, newCols, newVals, INSERT_VALUES);CHKERRQ(ierr);
442     }
443     ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
444     ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
445   }
446   ierr = PetscFree2(newCols,newVals);CHKERRQ(ierr);
447   PetscFunctionReturn(0);
448 }
449