Actual source code: ex12.c
1: /*$Id: ex12.c,v 1.29 2001/08/07 03:03:07 balay Exp $*/
3: static char help[] = "Tests the use of MatZeroRows() for parallel matrices.n
4: This example also tests the use of MatDuplicate() for both MPIAIJ and MPIBAIJ matrices";
6: #include petscmat.h
8: EXTERN int TestMatZeroRows_Basic(Mat,IS,PetscScalar *);
9: EXTERN int TestMatZeroRows_with_no_allocation(Mat,IS,PetscScalar *);
11: int main(int argc,char **args)
12: {
13: Mat A;
14: int i,j,m = 3,n,rank,size,I,J,ierr,Imax;
15: PetscScalar v,diag=-4.0;
16: IS is;
18: PetscInitialize(&argc,&args,(char *)0,help);
19: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
20: MPI_Comm_size(PETSC_COMM_WORLD,&size);
21: n = 2*size;
23: /* create A Square matrix for the five point stencil,YET AGAIN*/
24: MatCreate(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n,&A);
25: MatSetFromOptions(A);
26: for (i=0; i<m; i++) {
27: for (j=2*rank; j<2*rank+2; j++) {
28: v = -1.0; I = j + n*i;
29: if (i>0) {J = I - n; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
30: if (i<m-1) {J = I + n; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
31: if (j>0) {J = I - 1; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
32: if (j<n-1) {J = I + 1; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
33: v = 4.0; MatSetValues(A,1,&I,1,&I,&v,INSERT_VALUES);
34: }
35: }
36: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
37: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
39: /* Create AN IS required by MatZeroRows() */
40: Imax = n*rank; if (Imax>= n*m -m - 1) Imax = m*n - m - 1;
41: ISCreateStride(PETSC_COMM_SELF,m,Imax,1,&is);
43: TestMatZeroRows_Basic(A,is,PETSC_NULL);
44: TestMatZeroRows_Basic(A,is,&diag);
46: TestMatZeroRows_with_no_allocation(A,is,PETSC_NULL);
47: TestMatZeroRows_with_no_allocation(A,is,&diag);
49: MatDestroy(A);
51: /* Now Create a rectangular matrix with five point stencil (app)
52: n+size is used so that this dimension is always divisible by size.
53: This way, we can always use bs = size for any number of procs */
54: MatCreate(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m*n,m*(n+size),&A);
55: MatSetFromOptions(A);
56: for (i=0; i<m; i++) {
57: for (j=2*rank; j<2*rank+2; j++) {
58: v = -1.0; I = j + n*i;
59: if (i>0) {J = I - n; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
60: if (i<m-1) {J = I + n; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
61: if (j>0) {J = I - 1; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
62: if (j<n+size-1) {J = I + 1; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
63: v = 4.0; MatSetValues(A,1,&I,1,&I,&v,INSERT_VALUES);
64: }
65: }
66: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
67: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
69: TestMatZeroRows_Basic(A,is,PETSC_NULL);
70: TestMatZeroRows_Basic(A,is,&diag);
72: MatDestroy(A);
73: ISDestroy(is);
74: PetscFinalize();
75: return 0;
76: }
78: int TestMatZeroRows_Basic(Mat A,IS is,PetscScalar *diag)
79: {
80: Mat B;
81: int ierr;
82: PetscTruth keepzeroedrows;
84: /* Now copy A into B, and test it with MatZeroRows() */
85: MatDuplicate(A,MAT_COPY_VALUES,&B);
87: PetscOptionsHasName(PETSC_NULL,"-keep_zeroed_rows",&keepzeroedrows);
88: if (keepzeroedrows) {
89: MatSetOption(B,MAT_KEEP_ZEROED_ROWS);
90: }
92: MatZeroRows(B,is,diag);
93: MatView(B,PETSC_VIEWER_STDOUT_WORLD);
94: MatDestroy(B);
95: return 0;
96: }
98: int TestMatZeroRows_with_no_allocation(Mat A,IS is,PetscScalar *diag)
99: {
100: Mat B;
101: int ierr;
103: /* Now copy A into B, and test it with MatZeroRows() */
104: MatDuplicate(A,MAT_COPY_VALUES,&B);
105: /* Set this flag after assembly. This way, it affects only MatZeroRows() */
106: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR);
108: MatZeroRows(B,is,diag);
109: MatView(B,PETSC_VIEWER_STDOUT_WORLD);
110: MatDestroy(B);
111: return 0;
112: }