Actual source code: shellcnv.c
1: /*$Id: shellcnv.c,v 1.20 2001/08/07 03:02:51 balay Exp $*/
3: #include src/mat/matimpl.h
4: #include vecimpl.h
5:
8: int MatConvert_Shell(Mat oldmat,const MatType newtype,Mat *newmat) {
9: Mat mat;
10: Vec in,out;
11: int ierr,i,M,m,*rows,start,end;
12: MPI_Comm comm;
13: PetscScalar *array,zero = 0.0,one = 1.0;
16: comm = oldmat->comm;
18: MatGetOwnershipRange(oldmat,&start,&end);
19: VecCreateMPI(comm,end-start,PETSC_DECIDE,&in);
20: VecDuplicate(in,&out);
21: VecGetSize(in,&M);
22: VecGetLocalSize(in,&m);
23: PetscMalloc((m+1)*sizeof(int),&rows);
24: for (i=0; i<m; i++) {rows[i] = start + i;}
26: MatCreate(comm,m,M,M,M,&mat);
27: MatSetType(mat,newtype);
29: for (i=0; i<M; i++) {
30: VecSet(&zero,in);
31: VecSetValues(in,1,&i,&one,INSERT_VALUES);
32: VecAssemblyBegin(in);
33: VecAssemblyEnd(in);
35: MatMult(oldmat,in,out);
36:
37: VecGetArray(out,&array);
38: MatSetValues(mat,m,rows,1,&i,array,INSERT_VALUES);
39: VecRestoreArray(out,&array);
41: }
42: PetscFree(rows);
43: VecDestroy(in);
44: VecDestroy(out);
45: MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);
46: MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);
48: /* Fake support for "inplace" convert. */
49: if (*newmat == oldmat) {
50: MatDestroy(oldmat);
51: }
52: *newmat = mat;
53: return(0);
54: }