Actual source code: ex20.c
1: /*$Id: ex20.c,v 1.23 2001/08/07 03:03:07 balay Exp $*/
3: static char help[] = "Tests converting a matrix to another format with MatConvert().nn";
5: #include petscmat.h
7: int main(int argc,char **args)
8: {
9: Mat C,A;
10: int i,j,m = 5,n = 4,I,J,ierr,rank,size;
11: PetscScalar v;
12: char mtype[256];
14: PetscInitialize(&argc,&args,(char *)0,help);
15: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
17: /* This example does not work correctly for np > 2 */
18: MPI_Comm_size(PETSC_COMM_WORLD,&size);
19: if (size > 2) SETERRQ(1,"Use np <= 2");
21: /* Create the matrix for the five point stencil, YET AGAIN */
22: MatCreate(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n,&C);
23: MatSetFromOptions(C);
24: for (i=0; i<m; i++) {
25: for (j=2*rank; j<2*rank+2; j++) {
26: v = -1.0; I = j + n*i;
27: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
28: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
29: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
30: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
31: v = 4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
32: }
33: }
35: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
36: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
37: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO);
38: MatView(C,PETSC_VIEWER_STDOUT_WORLD);
39: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
40: MatView(C,PETSC_VIEWER_STDOUT_WORLD);
41:
42: PetscStrcpy(mtype,MATSAME);
43: PetscOptionsGetString(PETSC_NULL,"-conv_mat_type",mtype,256,PETSC_NULL);
44: MatConvert(C,mtype,&A);
45: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO);
46: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
47: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
48: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_IMPL);
49: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
51: /* Free data structures */
52: MatDestroy(A);
53: MatDestroy(C);
55: PetscFinalize();
56: return 0;
57: }