xref: /petsc/src/mat/utils/axpy.c (revision 8bc8193efbc389280f83b3d41dffa9e2d23e2ace) !
1 
2 #include "src/mat/matimpl.h"  /*I   "petscmat.h"  I*/
3 
4 #undef __FUNCT__
5 #define __FUNCT__ "MatAXPY"
6 /*@
7    MatAXPY - Computes Y = a*X + Y.
8 
9    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 or SUBSET_NONZERO_PATTERN
16 
17    Contributed by: Matthew Knepley
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(const PetscScalar *a,Mat X,Mat Y,MatStructure str)
29 {
30   PetscErrorCode ierr;
31   PetscInt       m1,m2,n1,n2;
32 
33   PetscFunctionBegin;
34   PetscValidScalarPointer(a,1);
35   PetscValidHeaderSpecific(X,MAT_COOKIE,2);
36   PetscValidHeaderSpecific(Y,MAT_COOKIE,3);
37 
38   ierr = MatGetSize(X,&m1,&n1);CHKERRQ(ierr);
39   ierr = MatGetSize(Y,&m2,&n2);CHKERRQ(ierr);
40   if (m1 != m2 || n1 != n2) SETERRQ4(PETSC_ERR_ARG_SIZ,"Non conforming matrix add: %D %D %D %D",m1,m2,n1,n2);
41 
42   if (X->ops->axpy) {
43     ierr = (*X->ops->axpy)(a,X,Y,str);CHKERRQ(ierr);
44   } else {
45     ierr = MatAXPY_Basic(a,X,Y,str);CHKERRQ(ierr);
46   }
47   PetscFunctionReturn(0);
48 }
49 
50 
51 #undef __FUNCT__
52 #define __FUNCT__ "MatAXPY_Basic"
53 PetscErrorCode MatAXPY_Basic(const PetscScalar *a,Mat X,Mat Y,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__ "MatShift"
89 /*@
90    MatShift - Computes Y =  Y + a I, where a is a PetscScalar and I is the identity matrix.
91 
92    Collective on Mat
93 
94    Input Parameters:
95 +  Y - the matrices
96 -  a - the PetscScalar
97 
98    Level: intermediate
99 
100 .keywords: matrix, add, shift
101 
102 .seealso: MatDiagonalSet()
103  @*/
104 PetscErrorCode MatShift(const PetscScalar *a,Mat Y)
105 {
106   PetscErrorCode ierr;
107   PetscInt       i,start,end;
108 
109   PetscFunctionBegin;
110   PetscValidScalarPointer(a,1);
111   PetscValidHeaderSpecific(Y,MAT_COOKIE,2);
112   MatPreallocated(Y);
113   if (!Y->assembled) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
114   if (Y->factor) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
115   if (Y->ops->shift) {
116     ierr = (*Y->ops->shift)(a,Y);CHKERRQ(ierr);
117   } else {
118     ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
119     for (i=start; i<end; i++) {
120       ierr = MatSetValues(Y,1,&i,1,&i,a,ADD_VALUES);CHKERRQ(ierr);
121     }
122     ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
123     ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
124   }
125   PetscFunctionReturn(0);
126 }
127 
128 #undef __FUNCT__
129 #define __FUNCT__ "MatDiagonalSet"
130 /*@
131    MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
132    that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
133    INSERT_VALUES.
134 
135    Input Parameters:
136 +  Y - the input matrix
137 .  D - the diagonal matrix, represented as a vector
138 -  i - INSERT_VALUES or ADD_VALUES
139 
140    Collective on Mat and Vec
141 
142    Level: intermediate
143 
144 .keywords: matrix, add, shift, diagonal
145 
146 .seealso: MatShift()
147 @*/
148 PetscErrorCode MatDiagonalSet(Mat Y,Vec D,InsertMode is)
149 {
150   PetscErrorCode ierr;
151   PetscInt       i,start,end;
152 
153   PetscFunctionBegin;
154   PetscValidHeaderSpecific(Y,MAT_COOKIE,1);
155   PetscValidHeaderSpecific(D,VEC_COOKIE,2);
156   if (Y->ops->diagonalset) {
157     ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
158   } else {
159     PetscInt    vstart,vend;
160     PetscScalar *v;
161     ierr = VecGetOwnershipRange(D,&vstart,&vend);CHKERRQ(ierr);
162     ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
163     if (vstart != start || vend != end) {
164       SETERRQ4(PETSC_ERR_ARG_SIZ,"Vector ownership range not compatible with matrix: %D %D vec %D %D mat",vstart,vend,start,end);
165     }
166     ierr = VecGetArray(D,&v);CHKERRQ(ierr);
167     for (i=start; i<end; i++) {
168       ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,is);CHKERRQ(ierr);
169     }
170     ierr = VecRestoreArray(D,&v);CHKERRQ(ierr);
171     ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
172     ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
173   }
174   PetscFunctionReturn(0);
175 }
176 
177 #undef __FUNCT__
178 #define __FUNCT__ "MatAYPX"
179 /*@
180    MatAYPX - Computes Y = X + a*Y.
181 
182    Collective on Mat
183 
184    Input Parameters:
185 +  X,Y - the matrices
186 -  a - the PetscScalar multiplier
187 
188    Contributed by: Matthew Knepley
189 
190    Notes:
191    This routine currently uses the MatAXPY() implementation.
192 
193    This is slow, if you need it fast send email to petsc-maint@mcs.anl.gov
194 
195    Level: intermediate
196 
197 .keywords: matrix, add
198 
199 .seealso: MatAXPY()
200  @*/
201 PetscErrorCode MatAYPX(const PetscScalar *a,Mat X,Mat Y)
202 {
203   PetscScalar    one = 1.0;
204   PetscErrorCode ierr;
205   PetscInt       mX,mY,nX,nY;
206 
207   PetscFunctionBegin;
208   PetscValidScalarPointer(a,1);
209   PetscValidHeaderSpecific(X,MAT_COOKIE,2);
210   PetscValidHeaderSpecific(Y,MAT_COOKIE,3);
211 
212   ierr = MatGetSize(X,&mX,&nX);CHKERRQ(ierr);
213   ierr = MatGetSize(X,&mY,&nY);CHKERRQ(ierr);
214   if (mX != mY || nX != nY) SETERRQ4(PETSC_ERR_ARG_SIZ,"Non conforming matrices: %D %D first %D %D second",mX,mY,nX,nY);
215 
216   ierr = MatScale(a,Y);CHKERRQ(ierr);
217   ierr = MatAXPY(&one,X,Y,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr);
218   PetscFunctionReturn(0);
219 }
220 
221 #undef __FUNCT__
222 #define __FUNCT__ "MatComputeExplicitOperator"
223 /*@
224     MatComputeExplicitOperator - Computes the explicit matrix
225 
226     Collective on Mat
227 
228     Input Parameter:
229 .   inmat - the matrix
230 
231     Output Parameter:
232 .   mat - the explict preconditioned operator
233 
234     Notes:
235     This computation is done by applying the operators to columns of the
236     identity matrix.
237 
238     Currently, this routine uses a dense matrix format when 1 processor
239     is used and a sparse format otherwise.  This routine is costly in general,
240     and is recommended for use only with relatively small systems.
241 
242     Level: advanced
243 
244 .keywords: Mat, compute, explicit, operator
245 
246 @*/
247 PetscErrorCode MatComputeExplicitOperator(Mat inmat,Mat *mat)
248 {
249   Vec            in,out;
250   PetscErrorCode ierr;
251   PetscInt       i,M,m,*rows,start,end;
252   MPI_Comm       comm;
253   PetscScalar    *array,zero = 0.0,one = 1.0;
254   PetscMPIInt    size;
255 
256   PetscFunctionBegin;
257   PetscValidHeaderSpecific(inmat,MAT_COOKIE,1);
258   PetscValidPointer(mat,2);
259 
260   comm = inmat->comm;
261   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
262 
263   ierr = MatGetLocalSize(inmat,&m,0);CHKERRQ(ierr);
264   ierr = MatGetSize(inmat,&M,0);CHKERRQ(ierr);
265   ierr = VecCreateMPI(comm,m,M,&in);CHKERRQ(ierr);
266   ierr = VecDuplicate(in,&out);CHKERRQ(ierr);
267   ierr = VecGetOwnershipRange(in,&start,&end);CHKERRQ(ierr);
268   ierr = PetscMalloc((m+1)*sizeof(PetscInt),&rows);CHKERRQ(ierr);
269   for (i=0; i<m; i++) {rows[i] = start + i;}
270 
271   ierr = MatCreate(comm,m,m,M,M,mat);CHKERRQ(ierr);
272   if (size == 1) {
273     ierr = MatSetType(*mat,MATSEQDENSE);CHKERRQ(ierr);
274 #if !defined(PETSC_USE_64BIT_INT)
275     ierr = MatSeqDenseSetPreallocation(*mat,PETSC_NULL);CHKERRQ(ierr);
276 #endif
277   } else {
278     ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
279     ierr = MatMPIAIJSetPreallocation(*mat,0,PETSC_NULL,0,PETSC_NULL);CHKERRQ(ierr);
280   }
281 
282   for (i=0; i<M; i++) {
283 
284     ierr = VecSet(&zero,in);CHKERRQ(ierr);
285     ierr = VecSetValues(in,1,&i,&one,INSERT_VALUES);CHKERRQ(ierr);
286     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
287     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
288 
289     ierr = MatMult(inmat,in,out);CHKERRQ(ierr);
290 
291     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
292     ierr = MatSetValues(*mat,m,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
293     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
294 
295   }
296   ierr = PetscFree(rows);CHKERRQ(ierr);
297   ierr = VecDestroy(out);CHKERRQ(ierr);
298   ierr = VecDestroy(in);CHKERRQ(ierr);
299   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
300   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
301   PetscFunctionReturn(0);
302 }
303 
304 /* Get the map xtoy which is used by MatAXPY() in the case of SUBSET_NONZERO_PATTERN */
305 #undef __FUNCT__
306 #define __FUNCT__ "MatAXPYGetxtoy_Private"
307 PetscErrorCode MatAXPYGetxtoy_Private(PetscInt m,PetscInt *xi,PetscInt *xj,PetscInt *xgarray, PetscInt *yi,PetscInt *yj,PetscInt *ygarray, PetscInt **xtoy)
308 {
309   PetscErrorCode ierr;
310   PetscInt       row,i,nz,xcol,ycol,jx,jy,*x2y;
311 
312   PetscFunctionBegin;
313   ierr = PetscMalloc(xi[m]*sizeof(PetscInt),&x2y);CHKERRQ(ierr);
314   i = 0;
315   for (row=0; row<m; row++){
316     nz = xi[1] - xi[0];
317     jy = 0;
318     for (jx=0; jx<nz; jx++,jy++){
319       if (xgarray && ygarray){
320         xcol = xgarray[xj[*xi + jx]];
321         ycol = ygarray[yj[*yi + jy]];
322       } else {
323         xcol = xj[*xi + jx];
324         ycol = yj[*yi + jy];  /* col index for y */
325       }
326       while ( ycol < xcol ) {
327         jy++;
328         if (ygarray){
329           ycol = ygarray[yj[*yi + jy]];
330         } else {
331           ycol = yj[*yi + jy];
332         }
333       }
334       if (xcol != ycol) SETERRQ2(PETSC_ERR_ARG_WRONG,"X matrix entry (%D,%D) is not in Y matrix",row,ycol);
335       x2y[i++] = *yi + jy;
336     }
337     xi++; yi++;
338   }
339   *xtoy = x2y;
340   PetscFunctionReturn(0);
341 }
342