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,const PetscScalar[] );
9: EXTERN int TestMatZeroRows_with_no_allocation(Mat,IS,const PetscScalar[]);
13: int main(int argc,char **args)
14: {
15: Mat A;
16: int i,j,m = 3,n,rank,size,I,J,ierr,Imax;
17: PetscScalar v,diag=-4.0;
18: IS is;
20: PetscInitialize(&argc,&args,(char *)0,help);
21: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
22: MPI_Comm_size(PETSC_COMM_WORLD,&size);
23: n = 2*size;
25: /* create A Square matrix for the five point stencil,YET AGAIN*/
26: MatCreate(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n,&A);
27: MatSetFromOptions(A);
28: for (i=0; i<m; i++) {
29: for (j=2*rank; j<2*rank+2; j++) {
30: v = -1.0; I = j + n*i;
31: if (i>0) {J = I - n; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
32: if (i<m-1) {J = I + n; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
33: if (j>0) {J = I - 1; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
34: if (j<n-1) {J = I + 1; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
35: v = 4.0; MatSetValues(A,1,&I,1,&I,&v,INSERT_VALUES);
36: }
37: }
38: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
39: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
41: /* Create AN IS required by MatZeroRows() */
42: Imax = n*rank; if (Imax>= n*m -m - 1) Imax = m*n - m - 1;
43: ISCreateStride(PETSC_COMM_SELF,m,Imax,1,&is);
45: TestMatZeroRows_Basic(A,is,PETSC_NULL);
46: TestMatZeroRows_Basic(A,is,&diag);
48: TestMatZeroRows_with_no_allocation(A,is,PETSC_NULL);
49: TestMatZeroRows_with_no_allocation(A,is,&diag);
51: MatDestroy(A);
53: /* Now Create a rectangular matrix with five point stencil (app)
54: n+size is used so that this dimension is always divisible by size.
55: This way, we can always use bs = size for any number of procs */
56: MatCreate(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m*n,m*(n+size),&A);
57: MatSetFromOptions(A);
58: for (i=0; i<m; i++) {
59: for (j=2*rank; j<2*rank+2; j++) {
60: v = -1.0; I = j + n*i;
61: if (i>0) {J = I - n; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
62: if (i<m-1) {J = I + n; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
63: if (j>0) {J = I - 1; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
64: if (j<n+size-1) {J = I + 1; MatSetValues(A,1,&I,1,&J,&v,INSERT_VALUES);}
65: v = 4.0; MatSetValues(A,1,&I,1,&I,&v,INSERT_VALUES);
66: }
67: }
68: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
69: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
71: TestMatZeroRows_Basic(A,is,PETSC_NULL);
72: TestMatZeroRows_Basic(A,is,&diag);
74: MatDestroy(A);
75: ISDestroy(is);
76: PetscFinalize();
77: return 0;
78: }
82: int TestMatZeroRows_Basic(Mat A,IS is,const PetscScalar diag[])
83: {
84: Mat B;
85: int ierr;
86: PetscTruth keepzeroedrows;
88: /* Now copy A into B, and test it with MatZeroRows() */
89: MatDuplicate(A,MAT_COPY_VALUES,&B);
91: PetscOptionsHasName(PETSC_NULL,"-keep_zeroed_rows",&keepzeroedrows);
92: if (keepzeroedrows) {
93: MatSetOption(B,MAT_KEEP_ZEROED_ROWS);
94: }
96: MatZeroRows(B,is,diag);
97: MatView(B,PETSC_VIEWER_STDOUT_WORLD);
98: MatDestroy(B);
99: return 0;
100: }
104: int TestMatZeroRows_with_no_allocation(Mat A,IS is,const PetscScalar diag[])
105: {
106: Mat B;
107: int ierr;
109: /* Now copy A into B, and test it with MatZeroRows() */
110: MatDuplicate(A,MAT_COPY_VALUES,&B);
111: /* Set this flag after assembly. This way, it affects only MatZeroRows() */
112: MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR);
114: MatZeroRows(B,is,diag);
115: MatView(B,PETSC_VIEWER_STDOUT_WORLD);
116: MatDestroy(B);
117: return 0;
118: }