xref: /petsc/src/mat/utils/axpy.c (revision 84df9cb40eca90ea9b18a456fab7a4ecc7f6c1a4)
1 
2 #include <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   PetscFunctionReturn(0);
45 }
46 
47 #undef __FUNCT__
48 #define __FUNCT__ "MatAXPY_Basic"
49 PetscErrorCode MatAXPY_Basic(Mat Y,PetscScalar a,Mat X,MatStructure str)
50 {
51   PetscInt          i,start,end,j,ncols,m,n;
52   PetscErrorCode    ierr;
53   const PetscInt    *row;
54   PetscScalar       *val;
55   const PetscScalar *vals;
56 
57   PetscFunctionBegin;
58   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
59   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
60   if (a == 1.0) {
61     for (i = start; i < end; i++) {
62       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
63       ierr = MatSetValues(Y,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
64       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
65     }
66   } else {
67     ierr = PetscMalloc((n+1)*sizeof(PetscScalar),&val);CHKERRQ(ierr);
68     for (i=start; i<end; i++) {
69       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
70       for (j=0; j<ncols; j++) {
71 	val[j] = a*vals[j];
72       }
73       ierr = MatSetValues(Y,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
74       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
75     }
76     ierr = PetscFree(val);CHKERRQ(ierr);
77   }
78   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
79   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
80   PetscFunctionReturn(0);
81 }
82 
83 #undef __FUNCT__
84 #define __FUNCT__ "MatAXPY_BasicWithPreallocation"
85 PetscErrorCode MatAXPY_BasicWithPreallocation(Mat B,Mat Y,PetscScalar a,Mat X,MatStructure str)
86 {
87   PetscInt          i,start,end,j,ncols,m,n;
88   PetscErrorCode    ierr;
89   const PetscInt    *row;
90   PetscScalar       *val;
91   const PetscScalar *vals;
92 
93   PetscFunctionBegin;
94   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
95   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
96   if (a == 1.0) {
97     for (i = start; i < end; i++) {
98       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
99       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
100       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
101 
102       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
103       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
104       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
105     }
106   } else {
107     ierr = PetscMalloc((n+1)*sizeof(PetscScalar),&val);CHKERRQ(ierr);
108     for (i=start; i<end; i++) {
109       ierr = MatGetRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
110       ierr = MatSetValues(B,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
111       ierr = MatRestoreRow(Y,i,&ncols,&row,&vals);CHKERRQ(ierr);
112 
113       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
114       for (j=0; j<ncols; j++) {
115 	val[j] = a*vals[j];
116       }
117       ierr = MatSetValues(B,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
118       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
119     }
120     ierr = PetscFree(val);CHKERRQ(ierr);
121   }
122   ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
123   ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
124   PetscFunctionReturn(0);
125 }
126 
127 #undef __FUNCT__
128 #define __FUNCT__ "MatShift"
129 /*@
130    MatShift - Computes Y =  Y + a I, where a is a PetscScalar and I is the identity matrix.
131 
132    Neighbor-wise Collective on Mat
133 
134    Input Parameters:
135 +  Y - the matrices
136 -  a - the PetscScalar
137 
138    Level: intermediate
139 
140 .keywords: matrix, add, shift
141 
142 .seealso: MatDiagonalSet()
143  @*/
144 PetscErrorCode  MatShift(Mat Y,PetscScalar a)
145 {
146   PetscErrorCode ierr;
147   PetscInt       i,start,end;
148 
149   PetscFunctionBegin;
150   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
151   if (!Y->assembled) SETERRQ(((PetscObject)Y)->comm,PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
152   if (Y->factortype) SETERRQ(((PetscObject)Y)->comm,PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
153   ierr = MatPreallocated(Y);CHKERRQ(ierr);
154 
155   if (Y->ops->shift) {
156     ierr = (*Y->ops->shift)(Y,a);CHKERRQ(ierr);
157   } else {
158     PetscScalar alpha = a;
159     ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
160     for (i=start; i<end; i++) {
161       ierr = MatSetValues(Y,1,&i,1,&i,&alpha,ADD_VALUES);CHKERRQ(ierr);
162     }
163     ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
164     ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
165   }
166   PetscFunctionReturn(0);
167 }
168 
169 #undef __FUNCT__
170 #define __FUNCT__ "MatDiagonalSet_Default"
171 PetscErrorCode  MatDiagonalSet_Default(Mat Y,Vec D,InsertMode is)
172 {
173   PetscErrorCode ierr;
174   PetscInt       i,start,end,vstart,vend;
175   PetscScalar    *v;
176 
177   PetscFunctionBegin;
178   ierr = VecGetOwnershipRange(D,&vstart,&vend);CHKERRQ(ierr);
179   ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
180   if (vstart != start || vend != end) {
181     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);
182   }
183   ierr = VecGetArray(D,&v);CHKERRQ(ierr);
184   for (i=start; i<end; i++) {
185     ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,is);CHKERRQ(ierr);
186   }
187   ierr = VecRestoreArray(D,&v);CHKERRQ(ierr);
188   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
189   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
190   PetscFunctionReturn(0);
191 }
192 
193 #undef __FUNCT__
194 #define __FUNCT__ "MatDiagonalSet"
195 /*@
196    MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
197    that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
198    INSERT_VALUES.
199 
200    Input Parameters:
201 +  Y - the input matrix
202 .  D - the diagonal matrix, represented as a vector
203 -  i - INSERT_VALUES or ADD_VALUES
204 
205    Neighbor-wise Collective on Mat and Vec
206 
207    Level: intermediate
208 
209 .keywords: matrix, add, shift, diagonal
210 
211 .seealso: MatShift()
212 @*/
213 PetscErrorCode  MatDiagonalSet(Mat Y,Vec D,InsertMode is)
214 {
215   PetscErrorCode ierr;
216 
217   PetscFunctionBegin;
218   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
219   PetscValidHeaderSpecific(D,VEC_CLASSID,2);
220   if (Y->ops->diagonalset) {
221     ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
222   } else {
223     ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
224   }
225   PetscFunctionReturn(0);
226 }
227 
228 #undef __FUNCT__
229 #define __FUNCT__ "MatAYPX"
230 /*@
231    MatAYPX - Computes Y = a*Y + X.
232 
233    Logically on Mat
234 
235    Input Parameters:
236 +  a - the PetscScalar multiplier
237 .  Y - the first matrix
238 .  X - the second matrix
239 -  str - either SAME_NONZERO_PATTERN, DIFFERENT_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
240 
241    Level: intermediate
242 
243 .keywords: matrix, add
244 
245 .seealso: MatAXPY()
246  @*/
247 PetscErrorCode  MatAYPX(Mat Y,PetscScalar a,Mat X,MatStructure str)
248 {
249   PetscScalar    one = 1.0;
250   PetscErrorCode ierr;
251   PetscInt       mX,mY,nX,nY;
252 
253   PetscFunctionBegin;
254   PetscValidHeaderSpecific(X,MAT_CLASSID,3);
255   PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
256   PetscValidLogicalCollectiveScalar(Y,a,2);
257   ierr = MatGetSize(X,&mX,&nX);CHKERRQ(ierr);
258   ierr = MatGetSize(X,&mY,&nY);CHKERRQ(ierr);
259   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);
260 
261   ierr = MatScale(Y,a);CHKERRQ(ierr);
262   ierr = MatAXPY(Y,one,X,str);CHKERRQ(ierr);
263   PetscFunctionReturn(0);
264 }
265 
266 #undef __FUNCT__
267 #define __FUNCT__ "MatComputeExplicitOperator"
268 /*@
269     MatComputeExplicitOperator - Computes the explicit matrix
270 
271     Collective on Mat
272 
273     Input Parameter:
274 .   inmat - the matrix
275 
276     Output Parameter:
277 .   mat - the explict preconditioned operator
278 
279     Notes:
280     This computation is done by applying the operators to columns of the
281     identity matrix.
282 
283     Currently, this routine uses a dense matrix format when 1 processor
284     is used and a sparse format otherwise.  This routine is costly in general,
285     and is recommended for use only with relatively small systems.
286 
287     Level: advanced
288 
289 .keywords: Mat, compute, explicit, operator
290 
291 @*/
292 PetscErrorCode  MatComputeExplicitOperator(Mat inmat,Mat *mat)
293 {
294   Vec            in,out;
295   PetscErrorCode ierr;
296   PetscInt       i,m,n,M,N,*rows,start,end;
297   MPI_Comm       comm;
298   PetscScalar    *array,zero = 0.0,one = 1.0;
299   PetscMPIInt    size;
300 
301   PetscFunctionBegin;
302   PetscValidHeaderSpecific(inmat,MAT_CLASSID,1);
303   PetscValidPointer(mat,2);
304 
305   comm = ((PetscObject)inmat)->comm;
306   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
307 
308   ierr = MatGetLocalSize(inmat,&m,&n);CHKERRQ(ierr);
309   ierr = MatGetSize(inmat,&M,&N);CHKERRQ(ierr);
310   ierr = MatGetVecs(inmat,&in,&out);CHKERRQ(ierr);
311   ierr = VecSetOption(in,VEC_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
312   ierr = VecGetOwnershipRange(out,&start,&end);CHKERRQ(ierr);
313   ierr = PetscMalloc(m*sizeof(PetscInt),&rows);CHKERRQ(ierr);
314   for (i=0; i<m; i++) {rows[i] = start + i;}
315 
316   ierr = MatCreate(comm,mat);CHKERRQ(ierr);
317   ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
318   if (size == 1) {
319     ierr = MatSetType(*mat,MATSEQDENSE);CHKERRQ(ierr);
320     ierr = MatSeqDenseSetPreallocation(*mat,PETSC_NULL);CHKERRQ(ierr);
321   } else {
322     ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
323     ierr = MatMPIAIJSetPreallocation(*mat,n,PETSC_NULL,N-n,PETSC_NULL);CHKERRQ(ierr);
324   }
325 
326   for (i=0; i<N; i++) {
327 
328     ierr = VecSet(in,zero);CHKERRQ(ierr);
329     ierr = VecSetValues(in,1,&i,&one,INSERT_VALUES);CHKERRQ(ierr);
330     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
331     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
332 
333     ierr = MatMult(inmat,in,out);CHKERRQ(ierr);
334 
335     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
336     ierr = MatSetValues(*mat,m,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
337     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
338 
339   }
340   ierr = PetscFree(rows);CHKERRQ(ierr);
341   ierr = VecDestroy(&out);CHKERRQ(ierr);
342   ierr = VecDestroy(&in);CHKERRQ(ierr);
343   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
344   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
345   PetscFunctionReturn(0);
346 }
347 
348 /* Get the map xtoy which is used by MatAXPY() in the case of SUBSET_NONZERO_PATTERN */
349 #undef __FUNCT__
350 #define __FUNCT__ "MatAXPYGetxtoy_Private"
351 PetscErrorCode MatAXPYGetxtoy_Private(PetscInt m,PetscInt *xi,PetscInt *xj,PetscInt *xgarray, PetscInt *yi,PetscInt *yj,PetscInt *ygarray, PetscInt **xtoy)
352 {
353   PetscErrorCode ierr;
354   PetscInt       row,i,nz,xcol,ycol,jx,jy,*x2y;
355 
356   PetscFunctionBegin;
357   ierr = PetscMalloc(xi[m]*sizeof(PetscInt),&x2y);CHKERRQ(ierr);
358   i = 0;
359   for (row=0; row<m; row++){
360     nz = xi[1] - xi[0];
361     jy = 0;
362     for (jx=0; jx<nz; jx++,jy++){
363       if (xgarray && ygarray){
364         xcol = xgarray[xj[*xi + jx]];
365         ycol = ygarray[yj[*yi + jy]];
366       } else {
367         xcol = xj[*xi + jx];
368         ycol = yj[*yi + jy];  /* col index for y */
369       }
370       while ( ycol < xcol ) {
371         jy++;
372         if (ygarray){
373           ycol = ygarray[yj[*yi + jy]];
374         } else {
375           ycol = yj[*yi + jy];
376         }
377       }
378       if (xcol != ycol) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"X matrix entry (%D,%D) is not in Y matrix",row,ycol);
379       x2y[i++] = *yi + jy;
380     }
381     xi++; yi++;
382   }
383   *xtoy = x2y;
384   PetscFunctionReturn(0);
385 }
386