xref: /petsc/src/mat/utils/axpy.c (revision bebe2cf65d55febe21a5af8db2bd2e168caaa2e7)
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 .keywords: matrix, add, shift
151 
152 .seealso: MatDiagonalSet()
153  @*/
154 PetscErrorCode  MatShift(Mat Y,PetscScalar a)
155 {
156   PetscErrorCode ierr;
157 
158   PetscFunctionBegin;
159   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
160   if (!Y->assembled) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
161   if (Y->factortype) SETERRQ(PetscObjectComm((PetscObject)Y),PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
162   MatCheckPreallocated(Y,1);
163 
164   ierr = (*Y->ops->shift)(Y,a);CHKERRQ(ierr);
165 
166 #if defined(PETSC_HAVE_CUSP)
167   if (Y->valid_GPU_matrix != PETSC_CUSP_UNALLOCATED) {
168     Y->valid_GPU_matrix = PETSC_CUSP_CPU;
169   }
170 #endif
171 #if defined(PETSC_HAVE_VIENNACL)
172   if (Y->valid_GPU_matrix != PETSC_VIENNACL_UNALLOCATED) {
173     Y->valid_GPU_matrix = PETSC_VIENNACL_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;
185   PetscScalar    *v;
186 
187   PetscFunctionBegin;
188   ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
189   ierr = VecGetArray(D,&v);CHKERRQ(ierr);
190   for (i=start; i<end; i++) {
191     ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,is);CHKERRQ(ierr);
192   }
193   ierr = VecRestoreArray(D,&v);CHKERRQ(ierr);
194   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
195   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
196   PetscFunctionReturn(0);
197 }
198 
199 #undef __FUNCT__
200 #define __FUNCT__ "MatDiagonalSet"
201 /*@
202    MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
203    that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
204    INSERT_VALUES.
205 
206    Input Parameters:
207 +  Y - the input matrix
208 .  D - the diagonal matrix, represented as a vector
209 -  i - INSERT_VALUES or ADD_VALUES
210 
211    Neighbor-wise Collective on Mat and Vec
212 
213    Level: intermediate
214 
215 .keywords: matrix, add, shift, diagonal
216 
217 .seealso: MatShift()
218 @*/
219 PetscErrorCode  MatDiagonalSet(Mat Y,Vec D,InsertMode is)
220 {
221   PetscErrorCode ierr;
222   PetscInt       matlocal,veclocal;
223 
224   PetscFunctionBegin;
225   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
226   PetscValidHeaderSpecific(D,VEC_CLASSID,2);
227   ierr = MatGetLocalSize(Y,&matlocal,NULL);CHKERRQ(ierr);
228   ierr = VecGetLocalSize(D,&veclocal);CHKERRQ(ierr);
229   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);
230   if (Y->ops->diagonalset) {
231     ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
232   } else {
233     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
234   }
235   PetscFunctionReturn(0);
236 }
237 
238 #undef __FUNCT__
239 #define __FUNCT__ "MatAYPX"
240 /*@
241    MatAYPX - Computes Y = a*Y + X.
242 
243    Logically on Mat
244 
245    Input Parameters:
246 +  a - the PetscScalar multiplier
247 .  Y - the first matrix
248 .  X - the second matrix
249 -  str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
250 
251    Level: intermediate
252 
253 .keywords: matrix, add
254 
255 .seealso: MatAXPY()
256  @*/
257 PetscErrorCode  MatAYPX(Mat Y,PetscScalar a,Mat X,MatStructure str)
258 {
259   PetscScalar    one = 1.0;
260   PetscErrorCode ierr;
261   PetscInt       mX,mY,nX,nY;
262 
263   PetscFunctionBegin;
264   PetscValidHeaderSpecific(X,MAT_CLASSID,3);
265   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
266   PetscValidLogicalCollectiveScalar(Y,a,2);
267   ierr = MatGetSize(X,&mX,&nX);CHKERRQ(ierr);
268   ierr = MatGetSize(X,&mY,&nY);CHKERRQ(ierr);
269   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);
270 
271   ierr = MatScale(Y,a);CHKERRQ(ierr);
272   ierr = MatAXPY(Y,one,X,str);CHKERRQ(ierr);
273   PetscFunctionReturn(0);
274 }
275 
276 #undef __FUNCT__
277 #define __FUNCT__ "MatComputeExplicitOperator"
278 /*@
279     MatComputeExplicitOperator - Computes the explicit matrix
280 
281     Collective on Mat
282 
283     Input Parameter:
284 .   inmat - the matrix
285 
286     Output Parameter:
287 .   mat - the explict preconditioned operator
288 
289     Notes:
290     This computation is done by applying the operators to columns of the
291     identity matrix.
292 
293     Currently, this routine uses a dense matrix format when 1 processor
294     is used and a sparse format otherwise.  This routine is costly in general,
295     and is recommended for use only with relatively small systems.
296 
297     Level: advanced
298 
299 .keywords: Mat, compute, explicit, operator
300 @*/
301 PetscErrorCode  MatComputeExplicitOperator(Mat inmat,Mat *mat)
302 {
303   Vec            in,out;
304   PetscErrorCode ierr;
305   PetscInt       i,m,n,M,N,*rows,start,end;
306   MPI_Comm       comm;
307   PetscScalar    *array,zero = 0.0,one = 1.0;
308   PetscMPIInt    size;
309 
310   PetscFunctionBegin;
311   PetscValidHeaderSpecific(inmat,MAT_CLASSID,1);
312   PetscValidPointer(mat,2);
313 
314   ierr = PetscObjectGetComm((PetscObject)inmat,&comm);CHKERRQ(ierr);
315   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
316 
317   ierr = MatGetLocalSize(inmat,&m,&n);CHKERRQ(ierr);
318   ierr = MatGetSize(inmat,&M,&N);CHKERRQ(ierr);
319   ierr = MatCreateVecs(inmat,&in,&out);CHKERRQ(ierr);
320   ierr = VecSetOption(in,VEC_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
321   ierr = VecGetOwnershipRange(out,&start,&end);CHKERRQ(ierr);
322   ierr = PetscMalloc1(m,&rows);CHKERRQ(ierr);
323   for (i=0; i<m; i++) rows[i] = start + i;
324 
325   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
326   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
327   if (size == 1) {
328     ierr = MatSetType(*mat,MATSEQDENSE);CHKERRQ(ierr);
329     ierr = MatSeqDenseSetPreallocation(*mat,NULL);CHKERRQ(ierr);
330   } else {
331     ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
332     ierr = MatMPIAIJSetPreallocation(*mat,n,NULL,N-n,NULL);CHKERRQ(ierr);
333   }
334 
335   for (i=0; i<N; i++) {
336 
337     ierr = VecSet(in,zero);CHKERRQ(ierr);
338     ierr = VecSetValues(in,1,&i,&one,INSERT_VALUES);CHKERRQ(ierr);
339     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
340     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
341 
342     ierr = MatMult(inmat,in,out);CHKERRQ(ierr);
343 
344     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
345     ierr = MatSetValues(*mat,m,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
346     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
347 
348   }
349   ierr = PetscFree(rows);CHKERRQ(ierr);
350   ierr = VecDestroy(&out);CHKERRQ(ierr);
351   ierr = VecDestroy(&in);CHKERRQ(ierr);
352   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
353   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
354   PetscFunctionReturn(0);
355 }
356 
357 #undef __FUNCT__
358 #define __FUNCT__ "MatChop"
359 /*@
360   MatChop - Set all values in the matrix less than the tolerance to zero
361 
362   Input Parameters:
363 + A   - The matrix
364 - tol - The zero tolerance
365 
366   Output Parameters:
367 . A - The chopped matrix
368 
369   Level: intermediate
370 
371 .seealso: MatCreate(), MatZeroEntries()
372  @*/
373 PetscErrorCode MatChop(Mat A, PetscReal tol)
374 {
375   PetscScalar    *newVals;
376   PetscInt       *newCols;
377   PetscInt       rStart, rEnd, numRows, maxRows, r, colMax = 0;
378   PetscErrorCode ierr;
379 
380   PetscFunctionBegin;
381   ierr = MatGetOwnershipRange(A, &rStart, &rEnd);CHKERRQ(ierr);
382   for (r = rStart; r < rEnd; ++r) {
383     PetscInt ncols;
384 
385     ierr   = MatGetRow(A, r, &ncols, NULL, NULL);CHKERRQ(ierr);
386     colMax = PetscMax(colMax, ncols);CHKERRQ(ierr);
387     ierr   = MatRestoreRow(A, r, &ncols, NULL, NULL);CHKERRQ(ierr);
388   }
389   numRows = rEnd - rStart;
390   ierr    = MPI_Allreduce(&numRows, &maxRows, 1, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)A));CHKERRQ(ierr);
391   ierr    = PetscMalloc2(colMax,&newCols,colMax,&newVals);CHKERRQ(ierr);
392   for (r = rStart; r < rStart+maxRows; ++r) {
393     const PetscScalar *vals;
394     const PetscInt    *cols;
395     PetscInt           ncols, newcols, c;
396 
397     if (r < rEnd) {
398       ierr = MatGetRow(A, r, &ncols, &cols, &vals);CHKERRQ(ierr);
399       for (c = 0; c < ncols; ++c) {
400         newCols[c] = cols[c];
401         newVals[c] = PetscAbsScalar(vals[c]) < tol ? 0.0 : vals[c];
402       }
403       newcols = ncols;
404       ierr = MatRestoreRow(A, r, &ncols, &cols, &vals);CHKERRQ(ierr);
405       ierr = MatSetValues(A, 1, &r, newcols, newCols, newVals, INSERT_VALUES);CHKERRQ(ierr);
406     }
407     ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
408     ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
409   }
410   ierr = PetscFree2(newCols,newVals);CHKERRQ(ierr);
411   PetscFunctionReturn(0);
412 }
413