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.\n\n";
5: #include petscmat.h
9: int main(int argc,char **args)
10: {
11: Mat C;
12: int i,j,m = 5,n = 2,I,J,ierr,rank,size;
13: PetscScalar v;
16: PetscInitialize(&argc,&args,(char *)0,help);
17: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
18: MPI_Comm_size(PETSC_COMM_WORLD,&size);
19: n = 2*size;
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: }
34: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
35: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
36: for (i=0; i<m; i++) {
37: for (j=2*rank; j<2*rank+2; j++) {
38: v = 1.0; I = j + n*i;
39: if (i>0) {J = I - n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
40: if (i<m-1) {J = I + n; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
41: if (j>0) {J = I - 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
42: if (j<n-1) {J = I + 1; MatSetValues(C,1,&I,1,&J,&v,INSERT_VALUES);}
43: v = -4.0; MatSetValues(C,1,&I,1,&I,&v,INSERT_VALUES);
44: }
45: }
46: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
47: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
49: MatView(C,PETSC_VIEWER_STDOUT_WORLD);
51: MatDestroy(C);
52: PetscFinalize();
53: return 0;
54: }