Actual source code: ex10.c
1: /*$Id: ex10.c,v 1.18 2001/08/07 03:03:07 balay Exp $*/
3: static char help[] = "Tests repeated use of assembly for matrices.nn";
5: #include petscmat.h
7: int main(int argc,char **args)
8: {
9: Mat C;
10: int i,j,m = 5,n = 2,I,J,ierr,rank,size;
11: PetscScalar v;
14: PetscInitialize(&argc,&args,(char *)0,help);
15: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
16: MPI_Comm_size(PETSC_COMM_WORLD,&size);
17: n = 2*size;
19: /* create the matrix for the five point stencil, YET AGAIN*/
20: MatCreate(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n,&C);
21: MatSetFromOptions(C);
22: for (i=0; i<m; i++) {
23: for (j=2*rank; j<2*rank+2; j++) {
24: v = -1.0; I = j + n*i;
25: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
26: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
27: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
28: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
29: v = 4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
30: }
31: }
32: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
33: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
34: for (i=0; i<m; i++) {
35: for (j=2*rank; j<2*rank+2; j++) {
36: v = 1.0; I = j + n*i;
37: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
38: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
39: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
40: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
41: v = -4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
42: }
43: }
44: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
45: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
47: MatView(C,PETSC_VIEWER_STDOUT_WORLD);
49: MatDestroy(C);
50: PetscFinalize();
51: return 0;
52: }