Actual source code: ex28.c
1: /*$Id: ex28.c,v 1.20 2001/03/23 23:22:29 balay Exp $*/
3: static char help[] = "Tests MatReorderForNonzeroDiagonal()nn";
5: #include "petscmat.h"
7: int main(int argc,char **args)
8: {
9: Mat A,LU;
10: Vec x,y;
11: int nnz[4]={2,1,1,1},col[4],i,ierr;
12: Scalar values[4];
13: IS rowperm,colperm;
15: PetscInitialize(&argc,&args,(char *)0,help);
17: MatCreateSeqAIJ(PETSC_COMM_WORLD,4,4,2,nnz,&A);
19: /* build test matrix */
20: values[0]=1.0;values[1]=-1.0;
21: col[0]=0;col[1]=2; i=0;
22: MatSetValues(A,1,&i,2,col,values,INSERT_VALUES);
23: values[0]=1.0;
24: col[0]=1;i=1;
25: MatSetValues(A,1,&i,1,col,values,INSERT_VALUES);
26: values[0]=-1.0;
27: col[0]=3;i=2;
28: MatSetValues(A,1,&i,1,col,values,INSERT_VALUES);
29: values[0]=1.0;
30: col[0]=2;i=3;
31: MatSetValues(A,1,&i,1,col,values,INSERT_VALUES);
32: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
33: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
34: MatView(A,PETSC_VIEWER_STDOUT_SELF);
36: MatGetOrdering(A,MATORDERING_NATURAL,&rowperm,&colperm);
37: MatReorderForNonzeroDiagonal(A,1.e-12,rowperm,colperm);
38: PetscPrintf(PETSC_COMM_SELF,"column and row permsn");
39: ISView(rowperm,0);
40: ISView(colperm,0);
41: MatLUFactorSymbolic(A,rowperm,colperm,PETSC_NULL,&LU);
42: MatLUFactorNumeric(A,&LU);
43: MatView(LU,PETSC_VIEWER_STDOUT_SELF);
44: VecCreate(PETSC_COMM_WORLD,PETSC_DECIDE,4,&x);
45: VecSetFromOptions(x);
46: VecDuplicate(x,&y);
47: values[0]=0;values[1]=1.0;values[2]=-1.0;values[3]=1.0;
48: for (i=0; i<4; i++) col[i]=i;
49: VecSetValues(x,4,col,values,INSERT_VALUES);
50: VecAssemblyBegin(x);
51: VecAssemblyEnd(x);
52: VecView(x,PETSC_VIEWER_STDOUT_SELF);
54: MatSolve(LU,x,y);
55: VecView(y,PETSC_VIEWER_STDOUT_SELF);
57: ISDestroy(rowperm);
58: ISDestroy(colperm);
59: MatDestroy(LU);
60: MatDestroy(A);
61: VecDestroy(x);
62: VecDestroy(y);
63: PetscFinalize();
64: return 0;
65: }