Actual source code: ex22.c
1: /*$Id: ex22.c,v 1.17 2001/08/07 03:03:07 balay Exp $*/
3: static char help[] = "Tests matrix ordering routines.nn";
5: #include petscmat.h
7: int main(int argc,char **args)
8: {
9: Mat C;
10: int i,j,m = 5,n = 5,I,J,ierr;
11: PetscScalar v;
12: IS perm,iperm;
14: PetscInitialize(&argc,&args,(char *)0,help);
16: MatCreateSeqAIJ(PETSC_COMM_SELF,m*n,m*n,5,PETSC_NULL,&C);
18: /* create the matrix for the five point stencil, YET AGAIN */
19: for (i=0; i<m; i++) {
20: for (j=0; j<n; j++) {
21: v = -1.0; I = j + n*i;
22: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
23: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
24: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
25: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
26: v = 4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
27: }
28: }
29: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
30: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
32: MatGetOrdering(C,MATORDERING_ND,&perm,&iperm);
33: ISView(perm,PETSC_VIEWER_STDOUT_SELF);
34: ISDestroy(perm);
35: ISDestroy(iperm);
37: MatGetOrdering(C,MATORDERING_RCM,&perm,&iperm);
38: ISView(perm,PETSC_VIEWER_STDOUT_SELF);
39: ISDestroy(perm);
40: ISDestroy(iperm);
42: MatGetOrdering(C,MATORDERING_QMD,&perm,&iperm);
43: ISView(perm,PETSC_VIEWER_STDOUT_SELF);
44: ISDestroy(perm);
45: ISDestroy(iperm);
47: MatDestroy(C);
48: PetscFinalize();
49: return 0;
50: }