xref: /petsc/src/mat/utils/axpy.c (revision 647798804180922dfb980ca29d2b49fa46af1416)
1 #define PETSCMAT_DLL
2 
3 #include "private/matimpl.h"  /*I   "petscmat.h"  I*/
4 
5 #undef __FUNCT__
6 #define __FUNCT__ "MatAXPY"
7 /*@
8    MatAXPY - Computes Y = a*X + Y.
9 
10    Logically  Collective on Mat
11 
12    Input Parameters:
13 +  a - the scalar multiplier
14 .  X - the first matrix
15 .  Y - the second matrix
16 -  str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN
17          or SUBSET_NONZERO_PATTERN (nonzeros of X is a subset of Y's)
18 
19    Notes:
20      Will only be efficient if one has the SAME_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
21 
22    Level: intermediate
23 
24 .keywords: matrix, add
25 
26 .seealso: MatAYPX()
27  @*/
28 PetscErrorCode  MatAXPY(Mat Y,PetscScalar a,Mat X,MatStructure str)
29 {
30   PetscErrorCode ierr;
31   PetscInt       m1,m2,n1,n2;
32 
33   PetscFunctionBegin;
34   PetscValidHeaderSpecific(X,MAT_CLASSID,3);
35   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
36   PetscValidLogicalCollectiveScalar(Y,a,2);
37   ierr = MatGetSize(X,&m1,&n1);CHKERRQ(ierr);
38   ierr = MatGetSize(Y,&m2,&n2);CHKERRQ(ierr);
39   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);
40 
41   ierr = PetscLogEventBegin(MAT_AXPY,Y,0,0,0);CHKERRQ(ierr);
42   if (Y->ops->axpy) {
43     ierr = (*Y->ops->axpy)(Y,a,X,str);CHKERRQ(ierr);
44   } else {
45     ierr = MatAXPY_Basic(Y,a,X,str);CHKERRQ(ierr);
46   }
47   ierr = PetscLogEventEnd(MAT_AXPY,Y,0,0,0);CHKERRQ(ierr);
48   PetscFunctionReturn(0);
49 }
50 
51 #undef __FUNCT__
52 #define __FUNCT__ "MatAXPY_Basic"
53 PetscErrorCode MatAXPY_Basic(Mat Y,PetscScalar a,Mat X,MatStructure str)
54 {
55   PetscInt          i,start,end,j,ncols,m,n;
56   PetscErrorCode    ierr;
57   const PetscInt    *row;
58   PetscScalar       *val;
59   const PetscScalar *vals;
60 
61   PetscFunctionBegin;
62   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
63   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
64   if (a == 1.0) {
65     for (i = start; i < end; i++) {
66       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
67       ierr = MatSetValues(Y,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
68       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
69     }
70   } else {
71     ierr = PetscMalloc((n+1)*sizeof(PetscScalar),&val);CHKERRQ(ierr);
72     for (i=start; i<end; i++) {
73       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
74       for (j=0; j<ncols; j++) {
75 	val[j] = a*vals[j];
76       }
77       ierr = MatSetValues(Y,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
78       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
79     }
80     ierr = PetscFree(val);CHKERRQ(ierr);
81   }
82   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
83   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
84   PetscFunctionReturn(0);
85 }
86 
87 #undef __FUNCT__
88 #define __FUNCT__ "MatAXPY_BasicWithPreallocation"
89 PetscErrorCode MatAXPY_BasicWithPreallocation(Mat B,Mat Y,PetscScalar a,Mat X,MatStructure str)
90 {
91   PetscInt          i,start,end,j,ncols,m,n;
92   PetscErrorCode    ierr;
93   const PetscInt    *row;
94   PetscScalar       *val;
95   const PetscScalar *vals;
96 
97   PetscFunctionBegin;
98   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
99   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
100   if (a == 1.0) {
101     for (i = start; i < end; i++) {
102       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
103       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
104       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
105 
106       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
107       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
108       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
109     }
110   } else {
111     ierr = PetscMalloc((n+1)*sizeof(PetscScalar),&val);CHKERRQ(ierr);
112     for (i=start; i<end; i++) {
113       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
114       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
115       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
116 
117       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
118       for (j=0; j<ncols; j++) {
119 	val[j] = a*vals[j];
120       }
121       ierr = MatSetValues(B,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
122       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
123     }
124     ierr = PetscFree(val);CHKERRQ(ierr);
125   }
126   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
127   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
128   PetscFunctionReturn(0);
129 }
130 
131 #undef __FUNCT__
132 #define __FUNCT__ "MatShift"
133 /*@
134    MatShift - Computes Y =  Y + a I, where a is a PetscScalar and I is the identity matrix.
135 
136    Neighbor-wise Collective on Mat
137 
138    Input Parameters:
139 +  Y - the matrices
140 -  a - the PetscScalar
141 
142    Level: intermediate
143 
144 .keywords: matrix, add, shift
145 
146 .seealso: MatDiagonalSet()
147  @*/
148 PetscErrorCode  MatShift(Mat Y,PetscScalar a)
149 {
150   PetscErrorCode ierr;
151   PetscInt       i,start,end;
152 
153   PetscFunctionBegin;
154   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
155   if (!Y->assembled) SETERRQ(((PetscObject)Y)->comm,PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
156   if (Y->factortype) SETERRQ(((PetscObject)Y)->comm,PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
157   ierr = MatPreallocated(Y);CHKERRQ(ierr);
158 
159   if (Y->ops->shift) {
160     ierr = (*Y->ops->shift)(Y,a);CHKERRQ(ierr);
161   } else {
162     PetscScalar alpha = a;
163     ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
164     for (i=start; i<end; i++) {
165       ierr = MatSetValues(Y,1,&i,1,&i,&alpha,ADD_VALUES);CHKERRQ(ierr);
166     }
167     ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
168     ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
169   }
170   PetscFunctionReturn(0);
171 }
172 
173 #undef __FUNCT__
174 #define __FUNCT__ "MatDiagonalSet_Default"
175 PetscErrorCode  MatDiagonalSet_Default(Mat Y,Vec D,InsertMode is)
176 {
177   PetscErrorCode ierr;
178   PetscInt       i,start,end,vstart,vend;
179   PetscScalar    *v;
180 
181   PetscFunctionBegin;
182   ierr = VecGetOwnershipRange(D,&vstart,&vend);CHKERRQ(ierr);
183   ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
184   if (vstart != start || vend != end) {
185     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);
186   }
187   ierr = VecGetArray(D,&v);CHKERRQ(ierr);
188   for (i=start; i<end; i++) {
189     ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,is);CHKERRQ(ierr);
190   }
191   ierr = VecRestoreArray(D,&v);CHKERRQ(ierr);
192   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
193   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
194   PetscFunctionReturn(0);
195 }
196 
197 #undef __FUNCT__
198 #define __FUNCT__ "MatDiagonalSet"
199 /*@
200    MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
201    that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
202    INSERT_VALUES.
203 
204    Input Parameters:
205 +  Y - the input matrix
206 .  D - the diagonal matrix, represented as a vector
207 -  i - INSERT_VALUES or ADD_VALUES
208 
209    Neighbor-wise Collective on Mat and Vec
210 
211    Level: intermediate
212 
213 .keywords: matrix, add, shift, diagonal
214 
215 .seealso: MatShift()
216 @*/
217 PetscErrorCode  MatDiagonalSet(Mat Y,Vec D,InsertMode is)
218 {
219   PetscErrorCode ierr;
220 
221   PetscFunctionBegin;
222   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
223   PetscValidHeaderSpecific(D,VEC_CLASSID,2);
224   if (Y->ops->diagonalset) {
225     ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
226   } else {
227     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
228   }
229   PetscFunctionReturn(0);
230 }
231 
232 #undef __FUNCT__
233 #define __FUNCT__ "MatAYPX"
234 /*@
235    MatAYPX - Computes Y = a*Y + X.
236 
237    Logically on Mat
238 
239    Input Parameters:
240 +  a - the PetscScalar multiplier
241 .  Y - the first matrix
242 .  X - the second matrix
243 -  str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
244 
245    Notes:
246      Will only be efficient if one has the SAME_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
247 
248    Level: intermediate
249 
250 .keywords: matrix, add
251 
252 .seealso: MatAXPY()
253  @*/
254 PetscErrorCode  MatAYPX(Mat Y,PetscScalar a,Mat X,MatStructure str)
255 {
256   PetscScalar    one = 1.0;
257   PetscErrorCode ierr;
258   PetscInt       mX,mY,nX,nY;
259 
260   PetscFunctionBegin;
261   PetscValidHeaderSpecific(X,MAT_CLASSID,3);
262   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
263   PetscValidLogicalCollectiveScalar(Y,a,2);
264   ierr = MatGetSize(X,&mX,&nX);CHKERRQ(ierr);
265   ierr = MatGetSize(X,&mY,&nY);CHKERRQ(ierr);
266   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);
267 
268   ierr = MatScale(Y,a);CHKERRQ(ierr);
269   ierr = MatAXPY(Y,one,X,str);CHKERRQ(ierr);
270   PetscFunctionReturn(0);
271 }
272 
273 #undef __FUNCT__
274 #define __FUNCT__ "MatComputeExplicitOperator"
275 /*@
276     MatComputeExplicitOperator - Computes the explicit matrix
277 
278     Collective on Mat
279 
280     Input Parameter:
281 .   inmat - the matrix
282 
283     Output Parameter:
284 .   mat - the explict preconditioned operator
285 
286     Notes:
287     This computation is done by applying the operators to columns of the
288     identity matrix.
289 
290     Currently, this routine uses a dense matrix format when 1 processor
291     is used and a sparse format otherwise.  This routine is costly in general,
292     and is recommended for use only with relatively small systems.
293 
294     Level: advanced
295 
296 .keywords: Mat, compute, explicit, operator
297 
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   comm = ((PetscObject)inmat)->comm;
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,PETSC_NULL);CHKERRQ(ierr);
328   } else {
329     ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
330     ierr = MatMPIAIJSetPreallocation(*mat,n,PETSC_NULL,N-n,PETSC_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