xref: /petsc/src/mat/impls/shell/shellcnv.c (revision 606d414c6e034e02e67059b83ebaefc3ebe99698)
1 #ifdef PETSC_RCS_HEADER
2 static char vcid[] = "$Id: shellcnv.c,v 1.7 1999/05/04 20:31:58 balay Exp balay $";
3 #endif
4 
5 
6 #include "petsc.h"
7 #include "src/mat/matimpl.h"        /*I "mat.h" I*/
8 #include "src/vec/vecimpl.h"
9 
10 #undef __FUNC__
11 #define __FUNC__ "MatConvert_Shell"
12 int MatConvert_Shell(Mat oldmat,MatType newtype, Mat *mat)
13 {
14   Vec      in,out;
15   int      ierr,i,M,m,size,*rows,start,end;
16   MPI_Comm comm;
17   Scalar   *array,zero = 0.0,one = 1.0;
18 
19   PetscFunctionBegin;
20   PetscValidHeaderSpecific(oldmat,MAT_COOKIE);
21   PetscValidPointer(mat);
22 
23   if (newtype != MATSEQDENSE || newtype != MATMPIDENSE) {
24     SETERRQ(PETSC_ERR_SUP,1,"Can only convert shell matrices to dense currently");
25   }
26   comm = oldmat->comm;
27 
28   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
29 
30   ierr = MatGetOwnershipRange(oldmat,&start,&end);CHKERRQ(ierr);
31   ierr = VecCreateMPI(comm,end-start,PETSC_DECIDE,&in);CHKERRQ(ierr);
32   ierr = VecDuplicate(in,&out);CHKERRQ(ierr);
33   ierr = VecGetSize(in,&M);CHKERRQ(ierr);
34   ierr = VecGetLocalSize(in,&m);CHKERRQ(ierr);
35   rows = (int *) PetscMalloc( (m+1)*sizeof(int) );CHKPTRQ(rows);
36   for ( i=0; i<m; i++ ) {rows[i] = start + i;}
37 
38   if (size == 1) {
39     ierr = MatCreateSeqDense(comm,M,M,PETSC_NULL,mat);CHKERRQ(ierr);
40   } else {
41     ierr = MatCreateMPIDense(comm,m,M,M,M,PETSC_NULL,mat);CHKERRQ(ierr);
42     /* ierr = MatCreateMPIAIJ(comm,m,m,M,M,0,0,0,0,mat);CHKERRQ(ierr); */
43   }
44 
45   for ( i=0; i<M; i++ ) {
46     ierr = VecSet(&zero,in);CHKERRQ(ierr);
47     ierr = VecSetValues(in,1,&i,&one,INSERT_VALUES);CHKERRQ(ierr);
48     ierr = VecAssemblyBegin(in);CHKERRQ(ierr);
49     ierr = VecAssemblyEnd(in);CHKERRQ(ierr);
50 
51     ierr = MatMult(oldmat,in,out);CHKERRQ(ierr);
52 
53     ierr = VecGetArray(out,&array);CHKERRQ(ierr);
54     ierr = MatSetValues(*mat,m,rows,1,&i,array,INSERT_VALUES);CHKERRQ(ierr);
55     ierr = VecRestoreArray(out,&array);CHKERRQ(ierr);
56 
57   }
58   ierr = PetscFree(rows);CHKERRQ(ierr);
59   ierr = VecDestroy(in);CHKERRQ(ierr);
60   ierr = VecDestroy(out);CHKERRQ(ierr);
61   ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
62   ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
63   PetscFunctionReturn(0);
64 }
65 
66 
67 
68