xref: /petsc/src/mat/utils/axpy.c (revision c094ef4021e955ef5f85f7d8a1bbc6ed64ba7621)
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 #if defined(PETSC_HAVE_VIENNACL)
50   if (Y->valid_GPU_matrix != PETSC_VIENNACL_UNALLOCATED) {
51     Y->valid_GPU_matrix = PETSC_VIENNACL_CPU;
52   }
53 #endif
54   PetscFunctionReturn(0);
55 }
56 
57 #undef __FUNCT__
58 #define __FUNCT__ "MatAXPY_Basic"
59 PetscErrorCode MatAXPY_Basic(Mat Y,PetscScalar a,Mat X,MatStructure str)
60 {
61   PetscInt          i,start,end,j,ncols,m,n;
62   PetscErrorCode    ierr;
63   const PetscInt    *row;
64   PetscScalar       *val;
65   const PetscScalar *vals;
66 
67   PetscFunctionBegin;
68   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
69   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
70   if (a == 1.0) {
71     for (i = start; i < end; i++) {
72       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
73       ierr = MatSetValues(Y,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
74       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
75     }
76   } else {
77     ierr = PetscMalloc1(n+1,&val);CHKERRQ(ierr);
78     for (i=start; i<end; i++) {
79       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
80       for (j=0; j<ncols; j++) {
81         val[j] = a*vals[j];
82       }
83       ierr = MatSetValues(Y,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
84       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
85     }
86     ierr = PetscFree(val);CHKERRQ(ierr);
87   }
88   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
89   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
90   PetscFunctionReturn(0);
91 }
92 
93 #undef __FUNCT__
94 #define __FUNCT__ "MatAXPY_BasicWithPreallocation"
95 PetscErrorCode MatAXPY_BasicWithPreallocation(Mat B,Mat Y,PetscScalar a,Mat X,MatStructure str)
96 {
97   PetscInt          i,start,end,j,ncols,m,n;
98   PetscErrorCode    ierr;
99   const PetscInt    *row;
100   PetscScalar       *val;
101   const PetscScalar *vals;
102 
103   PetscFunctionBegin;
104   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
105   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
106   if (a == 1.0) {
107     for (i = start; i < end; i++) {
108       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
109       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
110       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
111 
112       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
113       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
114       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
115     }
116   } else {
117     ierr = PetscMalloc1(n+1,&val);CHKERRQ(ierr);
118     for (i=start; i<end; i++) {
119       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
120       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
121       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
122 
123       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
124       for (j=0; j<ncols; j++) {
125         val[j] = a*vals[j];
126       }
127       ierr = MatSetValues(B,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
128       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
129     }
130     ierr = PetscFree(val);CHKERRQ(ierr);
131   }
132   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
133   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
134   PetscFunctionReturn(0);
135 }
136 
137 #undef __FUNCT__
138 #define __FUNCT__ "MatShift"
139 /*@
140    MatShift - Computes Y =  Y + a I, where a is a PetscScalar and I is the identity matrix.
141 
142    Neighbor-wise Collective on Mat
143 
144    Input Parameters:
145 +  Y - the matrices
146 -  a - the PetscScalar
147 
148    Level: intermediate
149 
150    Notes: If the matrix Y is missing some diagonal entries this routine can be very slow. To make it fast one should initially
151    fill the matrix so that all diagonal entries have a value (with a value of zero for those locations that would not have an
152    entry).
153 
154    Developers Note: If the local "diagonal part" of the matrix Y has no entries then the local diagonal part is
155     preallocated with 1 nonzero per row for the to be added values. This allows for fast shifting of an empty matrix.
156 
157 .keywords: matrix, add, shift
158 
159 .seealso: MatDiagonalSet()
160  @*/
161 PetscErrorCode  MatShift(Mat Y,PetscScalar a)
162 {
163   PetscErrorCode ierr;
164 
165   PetscFunctionBegin;
166   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
167   if (!Y->assembled) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
168   if (Y->factortype) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
169   MatCheckPreallocated(Y,1);
170 
171   ierr = (*Y->ops->shift)(Y,a);CHKERRQ(ierr);
172 
173 #if defined(PETSC_HAVE_CUSP)
174   if (Y->valid_GPU_matrix != PETSC_CUSP_UNALLOCATED) {
175     Y->valid_GPU_matrix = PETSC_CUSP_CPU;
176   }
177 #endif
178 #if defined(PETSC_HAVE_VIENNACL)
179   if (Y->valid_GPU_matrix != PETSC_VIENNACL_UNALLOCATED) {
180     Y->valid_GPU_matrix = PETSC_VIENNACL_CPU;
181   }
182 #endif
183   PetscFunctionReturn(0);
184 }
185 
186 #undef __FUNCT__
187 #define __FUNCT__ "MatDiagonalSet_Default"
188 PetscErrorCode  MatDiagonalSet_Default(Mat Y,Vec D,InsertMode is)
189 {
190   PetscErrorCode ierr;
191   PetscInt       i,start,end;
192   PetscScalar    *v;
193 
194   PetscFunctionBegin;
195   ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
196   ierr = VecGetArray(D,&v);CHKERRQ(ierr);
197   for (i=start; i<end; i++) {
198     ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,is);CHKERRQ(ierr);
199   }
200   ierr = VecRestoreArray(D,&v);CHKERRQ(ierr);
201   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
202   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
203   PetscFunctionReturn(0);
204 }
205 
206 #undef __FUNCT__
207 #define __FUNCT__ "MatDiagonalSet"
208 /*@
209    MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
210    that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
211    INSERT_VALUES.
212 
213    Input Parameters:
214 +  Y - the input matrix
215 .  D - the diagonal matrix, represented as a vector
216 -  i - INSERT_VALUES or ADD_VALUES
217 
218    Neighbor-wise Collective on Mat and Vec
219 
220    Notes: If the matrix Y is missing some diagonal entries this routine can be very slow. To make it fast one should initially
221    fill the matrix so that all diagonal entries have a value (with a value of zero for those locations that would not have an
222    entry).
223 
224    Level: intermediate
225 
226 .keywords: matrix, add, shift, diagonal
227 
228 .seealso: MatShift()
229 @*/
230 PetscErrorCode  MatDiagonalSet(Mat Y,Vec D,InsertMode is)
231 {
232   PetscErrorCode ierr;
233   PetscInt       matlocal,veclocal;
234 
235   PetscFunctionBegin;
236   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
237   PetscValidHeaderSpecific(D,VEC_CLASSID,2);
238   ierr = MatGetLocalSize(Y,&matlocal,NULL);CHKERRQ(ierr);
239   ierr = VecGetLocalSize(D,&veclocal);CHKERRQ(ierr);
240   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);
241   if (Y->ops->diagonalset) {
242     ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
243   } else {
244     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
245   }
246   PetscFunctionReturn(0);
247 }
248 
249 #undef __FUNCT__
250 #define __FUNCT__ "MatAYPX"
251 /*@
252    MatAYPX - Computes Y = a*Y + X.
253 
254    Logically on Mat
255 
256    Input Parameters:
257 +  a - the PetscScalar multiplier
258 .  Y - the first matrix
259 .  X - the second matrix
260 -  str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
261 
262    Level: intermediate
263 
264 .keywords: matrix, add
265 
266 .seealso: MatAXPY()
267  @*/
268 PetscErrorCode  MatAYPX(Mat Y,PetscScalar a,Mat X,MatStructure str)
269 {
270   PetscScalar    one = 1.0;
271   PetscErrorCode ierr;
272   PetscInt       mX,mY,nX,nY;
273 
274   PetscFunctionBegin;
275   PetscValidHeaderSpecific(X,MAT_CLASSID,3);
276   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
277   PetscValidLogicalCollectiveScalar(Y,a,2);
278   ierr = MatGetSize(X,&mX,&nX);CHKERRQ(ierr);
279   ierr = MatGetSize(X,&mY,&nY);CHKERRQ(ierr);
280   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);
281 
282   ierr = MatScale(Y,a);CHKERRQ(ierr);
283   ierr = MatAXPY(Y,one,X,str);CHKERRQ(ierr);
284   PetscFunctionReturn(0);
285 }
286 
287 #undef __FUNCT__
288 #define __FUNCT__ "MatComputeExplicitOperator"
289 /*@
290     MatComputeExplicitOperator - Computes the explicit matrix
291 
292     Collective on Mat
293 
294     Input Parameter:
295 .   inmat - the matrix
296 
297     Output Parameter:
298 .   mat - the explict preconditioned operator
299 
300     Notes:
301     This computation is done by applying the operators to columns of the
302     identity matrix.
303 
304     Currently, this routine uses a dense matrix format when 1 processor
305     is used and a sparse format otherwise.  This routine is costly in general,
306     and is recommended for use only with relatively small systems.
307 
308     Level: advanced
309 
310 .keywords: Mat, compute, explicit, operator
311 @*/
312 PetscErrorCode  MatComputeExplicitOperator(Mat inmat,Mat *mat)
313 {
314   Vec            in,out;
315   PetscErrorCode ierr;
316   PetscInt       i,m,n,M,N,*rows,start,end;
317   MPI_Comm       comm;
318   PetscScalar    *array,zero = 0.0,one = 1.0;
319   PetscMPIInt    size;
320 
321   PetscFunctionBegin;
322   PetscValidHeaderSpecific(inmat,MAT_CLASSID,1);
323   PetscValidPointer(mat,2);
324 
325   ierr = PetscObjectGetComm((PetscObject)inmat,&comm);CHKERRQ(ierr);
326   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
327 
328   ierr = MatGetLocalSize(inmat,&m,&n);CHKERRQ(ierr);
329   ierr = MatGetSize(inmat,&M,&N);CHKERRQ(ierr);
330   ierr = MatCreateVecs(inmat,&in,&out);CHKERRQ(ierr);
331   ierr = VecSetOption(in,VEC_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
332   ierr = VecGetOwnershipRange(out,&start,&end);CHKERRQ(ierr);
333   ierr = PetscMalloc1(m,&rows);CHKERRQ(ierr);
334   for (i=0; i<m; i++) rows[i] = start + i;
335 
336   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
337   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
338   if (size == 1) {
339     ierr = MatSetType(*mat,MATSEQDENSE);CHKERRQ(ierr);
340     ierr = MatSeqDenseSetPreallocation(*mat,NULL);CHKERRQ(ierr);
341   } else {
342     ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
343     ierr = MatMPIAIJSetPreallocation(*mat,n,NULL,N-n,NULL);CHKERRQ(ierr);
344   }
345 
346   for (i=0; i<N; i++) {
347 
348     ierr = VecSet(in,zero);CHKERRQ(ierr);
349     ierr = VecSetValues(in,1,&i,&one,INSERT_VALUES);CHKERRQ(ierr);
350     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
351     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
352 
353     ierr = MatMult(inmat,in,out);CHKERRQ(ierr);
354 
355     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
356     ierr = MatSetValues(*mat,m,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
357     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
358 
359   }
360   ierr = PetscFree(rows);CHKERRQ(ierr);
361   ierr = VecDestroy(&out);CHKERRQ(ierr);
362   ierr = VecDestroy(&in);CHKERRQ(ierr);
363   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
364   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
365   PetscFunctionReturn(0);
366 }
367 
368 #undef __FUNCT__
369 #define __FUNCT__ "MatChop"
370 /*@
371   MatChop - Set all values in the matrix less than the tolerance to zero
372 
373   Input Parameters:
374 + A   - The matrix
375 - tol - The zero tolerance
376 
377   Output Parameters:
378 . A - The chopped matrix
379 
380   Level: intermediate
381 
382 .seealso: MatCreate(), MatZeroEntries()
383  @*/
384 PetscErrorCode MatChop(Mat A, PetscReal tol)
385 {
386   PetscScalar    *newVals;
387   PetscInt       *newCols;
388   PetscInt       rStart, rEnd, numRows, maxRows, r, colMax = 0;
389   PetscErrorCode ierr;
390 
391   PetscFunctionBegin;
392   ierr = MatGetOwnershipRange(A, &rStart, &rEnd);CHKERRQ(ierr);
393   for (r = rStart; r < rEnd; ++r) {
394     PetscInt ncols;
395 
396     ierr   = MatGetRow(A, r, &ncols, NULL, NULL);CHKERRQ(ierr);
397     colMax = PetscMax(colMax, ncols);CHKERRQ(ierr);
398     ierr   = MatRestoreRow(A, r, &ncols, NULL, NULL);CHKERRQ(ierr);
399   }
400   numRows = rEnd - rStart;
401   ierr    = MPIU_Allreduce(&numRows, &maxRows, 1, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
402   ierr    = PetscMalloc2(colMax,&newCols,colMax,&newVals);CHKERRQ(ierr);
403   for (r = rStart; r < rStart+maxRows; ++r) {
404     const PetscScalar *vals;
405     const PetscInt    *cols;
406     PetscInt           ncols, newcols, c;
407 
408     if (r < rEnd) {
409       ierr = MatGetRow(A, r, &ncols, &cols, &vals);CHKERRQ(ierr);
410       for (c = 0; c < ncols; ++c) {
411         newCols[c] = cols[c];
412         newVals[c] = PetscAbsScalar(vals[c]) < tol ? 0.0 : vals[c];
413       }
414       newcols = ncols;
415       ierr = MatRestoreRow(A, r, &ncols, &cols, &vals);CHKERRQ(ierr);
416       ierr = MatSetValues(A, 1, &r, newcols, newCols, newVals, INSERT_VALUES);CHKERRQ(ierr);
417     }
418     ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
419     ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
420   }
421   ierr = PetscFree2(newCols,newVals);CHKERRQ(ierr);
422   PetscFunctionReturn(0);
423 }
424