xref: /petsc/src/mat/utils/axpy.c (revision 95dccacacae8a8fc0b691f9b4fba69a249b61188)
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 #elif defined(PETSC_HAVE_VIENNACL)
49   if (Y->valid_GPU_matrix != PETSC_VIENNACL_UNALLOCATED) {
50     Y->valid_GPU_matrix = PETSC_VIENNACL_CPU;
51   }
52 #elif defined(PETSC_HAVE_VECCUDA)
53   if (Y->valid_GPU_matrix != PETSC_CUDA_UNALLOCATED) {
54     Y->valid_GPU_matrix = PETSC_CUDA_CPU;
55   }
56 #endif
57   PetscFunctionReturn(0);
58 }
59 
60 #undef __FUNCT__
61 #define __FUNCT__ "MatAXPY_Basic"
62 PetscErrorCode MatAXPY_Basic(Mat Y,PetscScalar a,Mat X,MatStructure str)
63 {
64   PetscInt          i,start,end,j,ncols,m,n;
65   PetscErrorCode    ierr;
66   const PetscInt    *row;
67   PetscScalar       *val;
68   const PetscScalar *vals;
69 
70   PetscFunctionBegin;
71   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
72   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
73   if (a == 1.0) {
74     for (i = start; i < end; i++) {
75       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
76       ierr = MatSetValues(Y,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
77       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
78     }
79   } else {
80     ierr = PetscMalloc1(n+1,&val);CHKERRQ(ierr);
81     for (i=start; i<end; i++) {
82       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
83       for (j=0; j<ncols; j++) {
84         val[j] = a*vals[j];
85       }
86       ierr = MatSetValues(Y,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
87       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
88     }
89     ierr = PetscFree(val);CHKERRQ(ierr);
90   }
91   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
92   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
93   PetscFunctionReturn(0);
94 }
95 
96 #undef __FUNCT__
97 #define __FUNCT__ "MatAXPY_BasicWithPreallocation"
98 PetscErrorCode MatAXPY_BasicWithPreallocation(Mat B,Mat Y,PetscScalar a,Mat X,MatStructure str)
99 {
100   PetscInt          i,start,end,j,ncols,m,n;
101   PetscErrorCode    ierr;
102   const PetscInt    *row;
103   PetscScalar       *val;
104   const PetscScalar *vals;
105 
106   PetscFunctionBegin;
107   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
108   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
109   if (a == 1.0) {
110     for (i = start; i < end; i++) {
111       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
112       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
113       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
114 
115       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
116       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
117       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
118     }
119   } else {
120     ierr = PetscMalloc1(n+1,&val);CHKERRQ(ierr);
121     for (i=start; i<end; i++) {
122       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
123       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
124       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
125 
126       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
127       for (j=0; j<ncols; j++) {
128         val[j] = a*vals[j];
129       }
130       ierr = MatSetValues(B,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
131       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
132     }
133     ierr = PetscFree(val);CHKERRQ(ierr);
134   }
135   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
136   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
137   PetscFunctionReturn(0);
138 }
139 
140 #undef __FUNCT__
141 #define __FUNCT__ "MatShift"
142 /*@
143    MatShift - Computes Y =  Y + a I, where a is a PetscScalar and I is the identity matrix.
144 
145    Neighbor-wise Collective on Mat
146 
147    Input Parameters:
148 +  Y - the matrices
149 -  a - the PetscScalar
150 
151    Level: intermediate
152 
153    Notes: If the matrix Y is missing some diagonal entries this routine can be very slow. To make it fast one should initially
154    fill the matrix so that all diagonal entries have a value (with a value of zero for those locations that would not have an
155    entry).
156 
157    Developers Note: If the local "diagonal part" of the matrix Y has no entries then the local diagonal part is
158     preallocated with 1 nonzero per row for the to be added values. This allows for fast shifting of an empty matrix.
159 
160 .keywords: matrix, add, shift
161 
162 .seealso: MatDiagonalSet()
163  @*/
164 PetscErrorCode  MatShift(Mat Y,PetscScalar a)
165 {
166   PetscErrorCode ierr;
167 
168   PetscFunctionBegin;
169   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
170   if (!Y->assembled) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
171   if (Y->factortype) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
172   MatCheckPreallocated(Y,1);
173 
174   ierr = (*Y->ops->shift)(Y,a);CHKERRQ(ierr);
175 
176 #if defined(PETSC_HAVE_CUSP)
177   if (Y->valid_GPU_matrix != PETSC_CUSP_UNALLOCATED) {
178     Y->valid_GPU_matrix = PETSC_CUSP_CPU;
179   }
180 #elif defined(PETSC_HAVE_VIENNACL)
181   if (Y->valid_GPU_matrix != PETSC_VIENNACL_UNALLOCATED) {
182     Y->valid_GPU_matrix = PETSC_VIENNACL_CPU;
183   }
184 #elif defined(PETSC_HAVE_VECCUDA)
185   if (Y->valid_GPU_matrix != PETSC_CUDA_UNALLOCATED) {
186     Y->valid_GPU_matrix = PETSC_CUDA_CPU;
187   }
188 #endif
189   PetscFunctionReturn(0);
190 }
191 
192 #undef __FUNCT__
193 #define __FUNCT__ "MatDiagonalSet_Default"
194 PetscErrorCode  MatDiagonalSet_Default(Mat Y,Vec D,InsertMode is)
195 {
196   PetscErrorCode ierr;
197   PetscInt       i,start,end;
198   PetscScalar    *v;
199 
200   PetscFunctionBegin;
201   ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
202   ierr = VecGetArray(D,&v);CHKERRQ(ierr);
203   for (i=start; i<end; i++) {
204     ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,is);CHKERRQ(ierr);
205   }
206   ierr = VecRestoreArray(D,&v);CHKERRQ(ierr);
207   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
208   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
209   PetscFunctionReturn(0);
210 }
211 
212 #undef __FUNCT__
213 #define __FUNCT__ "MatDiagonalSet"
214 /*@
215    MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
216    that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
217    INSERT_VALUES.
218 
219    Input Parameters:
220 +  Y - the input matrix
221 .  D - the diagonal matrix, represented as a vector
222 -  i - INSERT_VALUES or ADD_VALUES
223 
224    Neighbor-wise Collective on Mat and Vec
225 
226    Notes: If the matrix Y is missing some diagonal entries this routine can be very slow. To make it fast one should initially
227    fill the matrix so that all diagonal entries have a value (with a value of zero for those locations that would not have an
228    entry).
229 
230    Level: intermediate
231 
232 .keywords: matrix, add, shift, diagonal
233 
234 .seealso: MatShift()
235 @*/
236 PetscErrorCode  MatDiagonalSet(Mat Y,Vec D,InsertMode is)
237 {
238   PetscErrorCode ierr;
239   PetscInt       matlocal,veclocal;
240 
241   PetscFunctionBegin;
242   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
243   PetscValidHeaderSpecific(D,VEC_CLASSID,2);
244   ierr = MatGetLocalSize(Y,&matlocal,NULL);CHKERRQ(ierr);
245   ierr = VecGetLocalSize(D,&veclocal);CHKERRQ(ierr);
246   if (matlocal != veclocal) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Number local rows of matrix %D does not match that of vector for diagonal %D",matlocal,veclocal);
247   if (Y->ops->diagonalset) {
248     ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
249   } else {
250     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
251   }
252   PetscFunctionReturn(0);
253 }
254 
255 #undef __FUNCT__
256 #define __FUNCT__ "MatAYPX"
257 /*@
258    MatAYPX - Computes Y = a*Y + X.
259 
260    Logically on Mat
261 
262    Input Parameters:
263 +  a - the PetscScalar multiplier
264 .  Y - the first matrix
265 .  X - the second matrix
266 -  str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
267 
268    Level: intermediate
269 
270 .keywords: matrix, add
271 
272 .seealso: MatAXPY()
273  @*/
274 PetscErrorCode  MatAYPX(Mat Y,PetscScalar a,Mat X,MatStructure str)
275 {
276   PetscScalar    one = 1.0;
277   PetscErrorCode ierr;
278   PetscInt       mX,mY,nX,nY;
279 
280   PetscFunctionBegin;
281   PetscValidHeaderSpecific(X,MAT_CLASSID,3);
282   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
283   PetscValidLogicalCollectiveScalar(Y,a,2);
284   ierr = MatGetSize(X,&mX,&nX);CHKERRQ(ierr);
285   ierr = MatGetSize(X,&mY,&nY);CHKERRQ(ierr);
286   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);
287 
288   ierr = MatScale(Y,a);CHKERRQ(ierr);
289   ierr = MatAXPY(Y,one,X,str);CHKERRQ(ierr);
290   PetscFunctionReturn(0);
291 }
292 
293 #undef __FUNCT__
294 #define __FUNCT__ "MatComputeExplicitOperator"
295 /*@
296     MatComputeExplicitOperator - Computes the explicit matrix
297 
298     Collective on Mat
299 
300     Input Parameter:
301 .   inmat - the matrix
302 
303     Output Parameter:
304 .   mat - the explict preconditioned operator
305 
306     Notes:
307     This computation is done by applying the operators to columns of the
308     identity matrix.
309 
310     Currently, this routine uses a dense matrix format when 1 processor
311     is used and a sparse format otherwise.  This routine is costly in general,
312     and is recommended for use only with relatively small systems.
313 
314     Level: advanced
315 
316 .keywords: Mat, compute, explicit, operator
317 @*/
318 PetscErrorCode  MatComputeExplicitOperator(Mat inmat,Mat *mat)
319 {
320   Vec            in,out;
321   PetscErrorCode ierr;
322   PetscInt       i,m,n,M,N,*rows,start,end;
323   MPI_Comm       comm;
324   PetscScalar    *array,zero = 0.0,one = 1.0;
325   PetscMPIInt    size;
326 
327   PetscFunctionBegin;
328   PetscValidHeaderSpecific(inmat,MAT_CLASSID,1);
329   PetscValidPointer(mat,2);
330 
331   ierr = PetscObjectGetComm((PetscObject)inmat,&comm);CHKERRQ(ierr);
332   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
333 
334   ierr = MatGetLocalSize(inmat,&m,&n);CHKERRQ(ierr);
335   ierr = MatGetSize(inmat,&M,&N);CHKERRQ(ierr);
336   ierr = MatCreateVecs(inmat,&in,&out);CHKERRQ(ierr);
337   ierr = VecSetOption(in,VEC_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
338   ierr = VecGetOwnershipRange(out,&start,&end);CHKERRQ(ierr);
339   ierr = PetscMalloc1(m,&rows);CHKERRQ(ierr);
340   for (i=0; i<m; i++) rows[i] = start + i;
341 
342   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
343   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
344   if (size == 1) {
345     ierr = MatSetType(*mat,MATSEQDENSE);CHKERRQ(ierr);
346     ierr = MatSeqDenseSetPreallocation(*mat,NULL);CHKERRQ(ierr);
347   } else {
348     ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
349     ierr = MatMPIAIJSetPreallocation(*mat,n,NULL,N-n,NULL);CHKERRQ(ierr);
350   }
351 
352   for (i=0; i<N; i++) {
353 
354     ierr = VecSet(in,zero);CHKERRQ(ierr);
355     ierr = VecSetValues(in,1,&i,&one,INSERT_VALUES);CHKERRQ(ierr);
356     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
357     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
358 
359     ierr = MatMult(inmat,in,out);CHKERRQ(ierr);
360 
361     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
362     ierr = MatSetValues(*mat,m,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
363     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
364 
365   }
366   ierr = PetscFree(rows);CHKERRQ(ierr);
367   ierr = VecDestroy(&out);CHKERRQ(ierr);
368   ierr = VecDestroy(&in);CHKERRQ(ierr);
369   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
370   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
371   PetscFunctionReturn(0);
372 }
373 
374 #undef __FUNCT__
375 #define __FUNCT__ "MatChop"
376 /*@
377   MatChop - Set all values in the matrix less than the tolerance to zero
378 
379   Input Parameters:
380 + A   - The matrix
381 - tol - The zero tolerance
382 
383   Output Parameters:
384 . A - The chopped matrix
385 
386   Level: intermediate
387 
388 .seealso: MatCreate(), MatZeroEntries()
389  @*/
390 PetscErrorCode MatChop(Mat A, PetscReal tol)
391 {
392   PetscScalar    *newVals;
393   PetscInt       *newCols;
394   PetscInt       rStart, rEnd, numRows, maxRows, r, colMax = 0;
395   PetscErrorCode ierr;
396 
397   PetscFunctionBegin;
398   ierr = MatGetOwnershipRange(A, &rStart, &rEnd);CHKERRQ(ierr);
399   for (r = rStart; r < rEnd; ++r) {
400     PetscInt ncols;
401 
402     ierr   = MatGetRow(A, r, &ncols, NULL, NULL);CHKERRQ(ierr);
403     colMax = PetscMax(colMax, ncols);CHKERRQ(ierr);
404     ierr   = MatRestoreRow(A, r, &ncols, NULL, NULL);CHKERRQ(ierr);
405   }
406   numRows = rEnd - rStart;
407   ierr    = MPIU_Allreduce(&numRows, &maxRows, 1, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
408   ierr    = PetscMalloc2(colMax,&newCols,colMax,&newVals);CHKERRQ(ierr);
409   for (r = rStart; r < rStart+maxRows; ++r) {
410     const PetscScalar *vals;
411     const PetscInt    *cols;
412     PetscInt           ncols, newcols, c;
413 
414     if (r < rEnd) {
415       ierr = MatGetRow(A, r, &ncols, &cols, &vals);CHKERRQ(ierr);
416       for (c = 0; c < ncols; ++c) {
417         newCols[c] = cols[c];
418         newVals[c] = PetscAbsScalar(vals[c]) < tol ? 0.0 : vals[c];
419       }
420       newcols = ncols;
421       ierr = MatRestoreRow(A, r, &ncols, &cols, &vals);CHKERRQ(ierr);
422       ierr = MatSetValues(A, 1, &r, newcols, newCols, newVals, INSERT_VALUES);CHKERRQ(ierr);
423     }
424     ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
425     ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
426   }
427   ierr = PetscFree2(newCols,newVals);CHKERRQ(ierr);
428   PetscFunctionReturn(0);
429 }
430