xref: /petsc/src/mat/tests/ex117.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 
2 static char help[] = "Tests Cholesky factorization for a SBAIJ matrix, (bs=2).\n";
3 /*
4   This code is modified from the code contributed by JUNWANG@uwm.edu on Apr 13, 2007
5 */
6 
7 #include <petscmat.h>
8 
9 int main(int argc,char **args)
10 {
11   Mat            mat,fact,B;
12   PetscInt       ind1[2],ind2[2];
13   PetscScalar    temp[4];
14   PetscInt       nnz[3];
15   IS             perm,colp;
16   MatFactorInfo  info;
17   PetscMPIInt    size;
18 
19   PetscFunctionBeginUser;
20   PetscCall(PetscInitialize(&argc,&args,0,help));
21   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
22   PetscCheck(size == 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!");
23 
24   nnz[0]=2;nnz[1]=1;nnz[2]=1;
25   PetscCall(MatCreateSeqSBAIJ(PETSC_COMM_SELF,2,6,6,0,nnz,&mat));
26 
27   ind1[0]=0;ind1[1]=1;
28   temp[0]=3;temp[1]=2;temp[2]=0;temp[3]=3;
29   PetscCall(MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES));
30   ind2[0]=4;ind2[1]=5;
31   temp[0]=1;temp[1]=1;temp[2]=2;temp[3]=1;
32   PetscCall(MatSetValues(mat,2,ind1,2,ind2,temp,INSERT_VALUES));
33   ind1[0]=2;ind1[1]=3;
34   temp[0]=4;temp[1]=1;temp[2]=1;temp[3]=5;
35   PetscCall(MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES));
36   ind1[0]=4;ind1[1]=5;
37   temp[0]=5;temp[1]=1;temp[2]=1;temp[3]=6;
38   PetscCall(MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES));
39 
40   PetscCall(MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY));
41   PetscCall(MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY));
42 
43   PetscCall(MatDuplicate(mat,MAT_SHARE_NONZERO_PATTERN,&B));
44   ind1[0]=0;ind1[1]=1;
45   temp[0]=3;temp[1]=2;temp[2]=0;temp[3]=3;
46   PetscCall(MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES));
47   ind2[0]=4;ind2[1]=5;
48   temp[0]=1;temp[1]=1;temp[2]=2;temp[3]=1;
49   PetscCall(MatSetValues(mat,2,ind1,2,ind2,temp,INSERT_VALUES));
50   ind1[0]=2;ind1[1]=3;
51   temp[0]=4;temp[1]=1;temp[2]=1;temp[3]=5;
52   PetscCall(MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES));
53   ind1[0]=4;ind1[1]=5;
54   temp[0]=5;temp[1]=1;temp[2]=1;temp[3]=6;
55   PetscCall(MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES));
56 
57   PetscCall(MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY));
58   PetscCall(MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY));
59 
60   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"mat: \n"));
61   PetscCall(MatView(mat,PETSC_VIEWER_STDOUT_SELF));
62 
63   /* begin cholesky factorization */
64   PetscCall(MatGetOrdering(mat,MATORDERINGNATURAL,&perm,&colp));
65   PetscCall(ISDestroy(&colp));
66 
67   info.fill=1.0;
68   PetscCall(MatGetFactor(mat,MATSOLVERPETSC,MAT_FACTOR_CHOLESKY,&fact));
69   PetscCall(MatCholeskyFactorSymbolic(fact,mat,perm,&info));
70   PetscCall(MatCholeskyFactorNumeric(fact,mat,&info));
71 
72   PetscCall(ISDestroy(&perm));
73   PetscCall(MatDestroy(&mat));
74   PetscCall(MatDestroy(&fact));
75   PetscCall(MatDestroy(&B));
76   PetscCall(PetscFinalize());
77   return 0;
78 }
79