xref: /petsc/src/mat/utils/axpy.c (revision be1d678a52e6eff2808b2fa31ae986cdbf03c9fe)
1 #define PETSCMAT_DLL
2 
3 #include "src/mat/matimpl.h"  /*I   "petscmat.h"  I*/
4 
5 #undef __FUNCT__
6 #define __FUNCT__ "MatAXPY"
7 /*@
8    MatAXPY - Computes Y = a*X + Y.
9 
10    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 or SUBSET_NONZERO_PATTERN
17 
18    Contributed by: Matthew Knepley
19 
20    Notes:
21      Will only be efficient if one has the SAME_NONZERO_PATTERN or SUBSET_NONZERO_PATTERN
22 
23    Level: intermediate
24 
25 .keywords: matrix, add
26 
27 .seealso: MatAYPX()
28  @*/
29 PetscErrorCode PETSCMAT_DLLEXPORT MatAXPY(const PetscScalar *a,Mat X,Mat Y,MatStructure str)
30 {
31   PetscErrorCode ierr;
32   PetscInt       m1,m2,n1,n2;
33 
34   PetscFunctionBegin;
35   PetscValidScalarPointer(a,1);
36   PetscValidHeaderSpecific(X,MAT_COOKIE,2);
37   PetscValidHeaderSpecific(Y,MAT_COOKIE,3);
38 
39   ierr = MatGetSize(X,&m1,&n1);CHKERRQ(ierr);
40   ierr = MatGetSize(Y,&m2,&n2);CHKERRQ(ierr);
41   if (m1 != m2 || n1 != n2) SETERRQ4(PETSC_ERR_ARG_SIZ,"Non conforming matrix add: %D %D %D %D",m1,m2,n1,n2);
42 
43   if (X->ops->axpy) {
44     ierr = (*X->ops->axpy)(a,X,Y,str);CHKERRQ(ierr);
45   } else {
46     ierr = MatAXPY_Basic(a,X,Y,str);CHKERRQ(ierr);
47   }
48   PetscFunctionReturn(0);
49 }
50 
51 
52 #undef __FUNCT__
53 #define __FUNCT__ "MatAXPY_Basic"
54 PetscErrorCode MatAXPY_Basic(const PetscScalar *a,Mat X,Mat Y,MatStructure str)
55 {
56   PetscInt          i,start,end,j,ncols,m,n;
57   PetscErrorCode    ierr;
58   const PetscInt    *row;
59   PetscScalar       *val;
60   const PetscScalar *vals;
61 
62   PetscFunctionBegin;
63   ierr = MatGetSize(X,&m,&n);CHKERRQ(ierr);
64   ierr = MatGetOwnershipRange(X,&start,&end);CHKERRQ(ierr);
65   if (*a == 1.0) {
66     for (i = start; i < end; i++) {
67       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
68       ierr = MatSetValues(Y,1,&i,ncols,row,vals,ADD_VALUES);CHKERRQ(ierr);
69       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
70     }
71   } else {
72     ierr = PetscMalloc((n+1)*sizeof(PetscScalar),&val);CHKERRQ(ierr);
73     for (i=start; i<end; i++) {
74       ierr = MatGetRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
75       for (j=0; j<ncols; j++) {
76 	val[j] = (*a)*vals[j];
77       }
78       ierr = MatSetValues(Y,1,&i,ncols,row,val,ADD_VALUES);CHKERRQ(ierr);
79       ierr = MatRestoreRow(X,i,&ncols,&row,&vals);CHKERRQ(ierr);
80     }
81     ierr = PetscFree(val);CHKERRQ(ierr);
82   }
83   ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
84   ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
85   PetscFunctionReturn(0);
86 }
87 
88 #undef __FUNCT__
89 #define __FUNCT__ "MatShift"
90 /*@
91    MatShift - Computes Y =  Y + a I, where a is a PetscScalar and I is the identity matrix.
92 
93    Collective on Mat
94 
95    Input Parameters:
96 +  Y - the matrices
97 -  a - the PetscScalar
98 
99    Level: intermediate
100 
101 .keywords: matrix, add, shift
102 
103 .seealso: MatDiagonalSet()
104  @*/
105 PetscErrorCode PETSCMAT_DLLEXPORT MatShift(const PetscScalar *a,Mat Y)
106 {
107   PetscErrorCode ierr;
108   PetscInt       i,start,end;
109 
110   PetscFunctionBegin;
111   PetscValidScalarPointer(a,1);
112   PetscValidHeaderSpecific(Y,MAT_COOKIE,2);
113   MatPreallocated(Y);
114   if (!Y->assembled) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Not for unassembled matrix");
115   if (Y->factor) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
116   if (Y->ops->shift) {
117     ierr = (*Y->ops->shift)(a,Y);CHKERRQ(ierr);
118   } else {
119     ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
120     for (i=start; i<end; i++) {
121       ierr = MatSetValues(Y,1,&i,1,&i,a,ADD_VALUES);CHKERRQ(ierr);
122     }
123     ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
124     ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
125   }
126   PetscFunctionReturn(0);
127 }
128 
129 #undef __FUNCT__
130 #define __FUNCT__ "MatDiagonalSet"
131 /*@
132    MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
133    that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
134    INSERT_VALUES.
135 
136    Input Parameters:
137 +  Y - the input matrix
138 .  D - the diagonal matrix, represented as a vector
139 -  i - INSERT_VALUES or ADD_VALUES
140 
141    Collective on Mat and Vec
142 
143    Level: intermediate
144 
145 .keywords: matrix, add, shift, diagonal
146 
147 .seealso: MatShift()
148 @*/
149 PetscErrorCode PETSCMAT_DLLEXPORT MatDiagonalSet(Mat Y,Vec D,InsertMode is)
150 {
151   PetscErrorCode ierr;
152   PetscInt       i,start,end;
153 
154   PetscFunctionBegin;
155   PetscValidHeaderSpecific(Y,MAT_COOKIE,1);
156   PetscValidHeaderSpecific(D,VEC_COOKIE,2);
157   if (Y->ops->diagonalset) {
158     ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
159   } else {
160     PetscInt    vstart,vend;
161     PetscScalar *v;
162     ierr = VecGetOwnershipRange(D,&vstart,&vend);CHKERRQ(ierr);
163     ierr = MatGetOwnershipRange(Y,&start,&end);CHKERRQ(ierr);
164     if (vstart != start || vend != end) {
165       SETERRQ4(PETSC_ERR_ARG_SIZ,"Vector ownership range not compatible with matrix: %D %D vec %D %D mat",vstart,vend,start,end);
166     }
167     ierr = VecGetArray(D,&v);CHKERRQ(ierr);
168     for (i=start; i<end; i++) {
169       ierr = MatSetValues(Y,1,&i,1,&i,v+i-start,is);CHKERRQ(ierr);
170     }
171     ierr = VecRestoreArray(D,&v);CHKERRQ(ierr);
172     ierr = MatAssemblyBegin(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
173     ierr = MatAssemblyEnd(Y,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
174   }
175   PetscFunctionReturn(0);
176 }
177 
178 #undef __FUNCT__
179 #define __FUNCT__ "MatAYPX"
180 /*@
181    MatAYPX - Computes Y = X + a*Y.
182 
183    Collective on Mat
184 
185    Input Parameters:
186 +  X,Y - the matrices
187 -  a - the PetscScalar multiplier
188 
189    Contributed by: Matthew Knepley
190 
191    Notes:
192    This routine currently uses the MatAXPY() implementation.
193 
194    This is slow, if you need it fast send email to petsc-maint@mcs.anl.gov
195 
196    Level: intermediate
197 
198 .keywords: matrix, add
199 
200 .seealso: MatAXPY()
201  @*/
202 PetscErrorCode PETSCMAT_DLLEXPORT MatAYPX(const PetscScalar *a,Mat X,Mat Y)
203 {
204   PetscScalar    one = 1.0;
205   PetscErrorCode ierr;
206   PetscInt       mX,mY,nX,nY;
207 
208   PetscFunctionBegin;
209   PetscValidScalarPointer(a,1);
210   PetscValidHeaderSpecific(X,MAT_COOKIE,2);
211   PetscValidHeaderSpecific(Y,MAT_COOKIE,3);
212 
213   ierr = MatGetSize(X,&mX,&nX);CHKERRQ(ierr);
214   ierr = MatGetSize(X,&mY,&nY);CHKERRQ(ierr);
215   if (mX != mY || nX != nY) SETERRQ4(PETSC_ERR_ARG_SIZ,"Non conforming matrices: %D %D first %D %D second",mX,mY,nX,nY);
216 
217   ierr = MatScale(a,Y);CHKERRQ(ierr);
218   ierr = MatAXPY(&one,X,Y,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr);
219   PetscFunctionReturn(0);
220 }
221 
222 #undef __FUNCT__
223 #define __FUNCT__ "MatComputeExplicitOperator"
224 /*@
225     MatComputeExplicitOperator - Computes the explicit matrix
226 
227     Collective on Mat
228 
229     Input Parameter:
230 .   inmat - the matrix
231 
232     Output Parameter:
233 .   mat - the explict preconditioned operator
234 
235     Notes:
236     This computation is done by applying the operators to columns of the
237     identity matrix.
238 
239     Currently, this routine uses a dense matrix format when 1 processor
240     is used and a sparse format otherwise.  This routine is costly in general,
241     and is recommended for use only with relatively small systems.
242 
243     Level: advanced
244 
245 .keywords: Mat, compute, explicit, operator
246 
247 @*/
248 PetscErrorCode PETSCMAT_DLLEXPORT MatComputeExplicitOperator(Mat inmat,Mat *mat)
249 {
250   Vec            in,out;
251   PetscErrorCode ierr;
252   PetscInt       i,M,m,*rows,start,end;
253   MPI_Comm       comm;
254   PetscScalar    *array,zero = 0.0,one = 1.0;
255   PetscMPIInt    size;
256 
257   PetscFunctionBegin;
258   PetscValidHeaderSpecific(inmat,MAT_COOKIE,1);
259   PetscValidPointer(mat,2);
260 
261   comm = inmat->comm;
262   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
263 
264   ierr = MatGetLocalSize(inmat,&m,0);CHKERRQ(ierr);
265   ierr = MatGetSize(inmat,&M,0);CHKERRQ(ierr);
266   ierr = VecCreateMPI(comm,m,M,&in);CHKERRQ(ierr);
267   ierr = VecDuplicate(in,&out);CHKERRQ(ierr);
268   ierr = VecGetOwnershipRange(in,&start,&end);CHKERRQ(ierr);
269   ierr = PetscMalloc((m+1)*sizeof(PetscInt),&rows);CHKERRQ(ierr);
270   for (i=0; i<m; i++) {rows[i] = start + i;}
271 
272   ierr = MatCreate(comm,m,m,M,M,mat);CHKERRQ(ierr);
273   if (size == 1) {
274     ierr = MatSetType(*mat,MATSEQDENSE);CHKERRQ(ierr);
275 #if !defined(PETSC_USE_64BIT_INT)
276     ierr = MatSeqDenseSetPreallocation(*mat,PETSC_NULL);CHKERRQ(ierr);
277 #endif
278   } else {
279     ierr = MatSetType(*mat,MATMPIAIJ);CHKERRQ(ierr);
280     ierr = MatMPIAIJSetPreallocation(*mat,0,PETSC_NULL,0,PETSC_NULL);CHKERRQ(ierr);
281   }
282 
283   for (i=0; i<M; i++) {
284 
285     ierr = VecSet(&zero,in);CHKERRQ(ierr);
286     ierr = VecSetValues(in,1,&i,&one,INSERT_VALUES);CHKERRQ(ierr);
287     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
288     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
289 
290     ierr = MatMult(inmat,in,out);CHKERRQ(ierr);
291 
292     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
293     ierr = MatSetValues(*mat,m,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
294     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
295 
296   }
297   ierr = PetscFree(rows);CHKERRQ(ierr);
298   ierr = VecDestroy(out);CHKERRQ(ierr);
299   ierr = VecDestroy(in);CHKERRQ(ierr);
300   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
301   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
302   PetscFunctionReturn(0);
303 }
304 
305 /* Get the map xtoy which is used by MatAXPY() in the case of SUBSET_NONZERO_PATTERN */
306 #undef __FUNCT__
307 #define __FUNCT__ "MatAXPYGetxtoy_Private"
308 PetscErrorCode MatAXPYGetxtoy_Private(PetscInt m,PetscInt *xi,PetscInt *xj,PetscInt *xgarray, PetscInt *yi,PetscInt *yj,PetscInt *ygarray, PetscInt **xtoy)
309 {
310   PetscErrorCode ierr;
311   PetscInt       row,i,nz,xcol,ycol,jx,jy,*x2y;
312 
313   PetscFunctionBegin;
314   ierr = PetscMalloc(xi[m]*sizeof(PetscInt),&x2y);CHKERRQ(ierr);
315   i = 0;
316   for (row=0; row<m; row++){
317     nz = xi[1] - xi[0];
318     jy = 0;
319     for (jx=0; jx<nz; jx++,jy++){
320       if (xgarray && ygarray){
321         xcol = xgarray[xj[*xi + jx]];
322         ycol = ygarray[yj[*yi + jy]];
323       } else {
324         xcol = xj[*xi + jx];
325         ycol = yj[*yi + jy];  /* col index for y */
326       }
327       while ( ycol < xcol ) {
328         jy++;
329         if (ygarray){
330           ycol = ygarray[yj[*yi + jy]];
331         } else {
332           ycol = yj[*yi + jy];
333         }
334       }
335       if (xcol != ycol) SETERRQ2(PETSC_ERR_ARG_WRONG,"X matrix entry (%D,%D) is not in Y matrix",row,ycol);
336       x2y[i++] = *yi + jy;
337     }
338     xi++; yi++;
339   }
340   *xtoy = x2y;
341   PetscFunctionReturn(0);
342 }
343