xref: /petsc/src/mat/tests/ex117.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
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   PetscErrorCode ierr;
12   Mat            mat,fact,B;
13   PetscInt       ind1[2],ind2[2];
14   PetscScalar    temp[4];
15   PetscInt       nnz[3];
16   IS             perm,colp;
17   MatFactorInfo  info;
18   PetscMPIInt    size;
19 
20   ierr = PetscInitialize(&argc,&args,0,help);if (ierr) return ierr;
21   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
22   if (size != 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"This is a uniprocessor example only!");
23 
24   nnz[0]=2;nnz[1]=1;nnz[2]=1;
25   ierr   = MatCreateSeqSBAIJ(PETSC_COMM_SELF,2,6,6,0,nnz,&mat);CHKERRQ(ierr);
26 
27   ind1[0]=0;ind1[1]=1;
28   temp[0]=3;temp[1]=2;temp[2]=0;temp[3]=3;
29   ierr   = MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES);CHKERRQ(ierr);
30   ind2[0]=4;ind2[1]=5;
31   temp[0]=1;temp[1]=1;temp[2]=2;temp[3]=1;
32   ierr   = MatSetValues(mat,2,ind1,2,ind2,temp,INSERT_VALUES);CHKERRQ(ierr);
33   ind1[0]=2;ind1[1]=3;
34   temp[0]=4;temp[1]=1;temp[2]=1;temp[3]=5;
35   ierr   = MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES);CHKERRQ(ierr);
36   ind1[0]=4;ind1[1]=5;
37   temp[0]=5;temp[1]=1;temp[2]=1;temp[3]=6;
38   ierr   = MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES);CHKERRQ(ierr);
39 
40   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
41   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
42 
43   ierr   = MatDuplicate(mat,MAT_SHARE_NONZERO_PATTERN,&B);CHKERRQ(ierr);
44   ind1[0]=0;ind1[1]=1;
45   temp[0]=3;temp[1]=2;temp[2]=0;temp[3]=3;
46   ierr   = MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES);CHKERRQ(ierr);
47   ind2[0]=4;ind2[1]=5;
48   temp[0]=1;temp[1]=1;temp[2]=2;temp[3]=1;
49   ierr   = MatSetValues(mat,2,ind1,2,ind2,temp,INSERT_VALUES);CHKERRQ(ierr);
50   ind1[0]=2;ind1[1]=3;
51   temp[0]=4;temp[1]=1;temp[2]=1;temp[3]=5;
52   ierr   = MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES);CHKERRQ(ierr);
53   ind1[0]=4;ind1[1]=5;
54   temp[0]=5;temp[1]=1;temp[2]=1;temp[3]=6;
55   ierr   = MatSetValues(mat,2,ind1,2,ind1,temp,INSERT_VALUES);CHKERRQ(ierr);
56 
57   ierr = MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
58   ierr = MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
59 
60   ierr = PetscPrintf(PETSC_COMM_WORLD,"mat: \n");CHKERRQ(ierr);
61   ierr = MatView(mat,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
62 
63   /* begin cholesky factorization */
64   ierr = MatGetOrdering(mat,MATORDERINGNATURAL,&perm,&colp);CHKERRQ(ierr);
65   ierr = ISDestroy(&colp);CHKERRQ(ierr);
66 
67   info.fill=1.0;
68   ierr = MatGetFactor(mat,MATSOLVERPETSC,MAT_FACTOR_CHOLESKY,&fact);CHKERRQ(ierr);
69   ierr = MatCholeskyFactorSymbolic(fact,mat,perm,&info);CHKERRQ(ierr);
70   ierr = MatCholeskyFactorNumeric(fact,mat,&info);CHKERRQ(ierr);
71 
72   ierr = ISDestroy(&perm);CHKERRQ(ierr);
73   ierr = MatDestroy(&mat);CHKERRQ(ierr);
74   ierr = MatDestroy(&fact);CHKERRQ(ierr);
75   ierr = MatDestroy(&B);CHKERRQ(ierr);
76   ierr = PetscFinalize();
77   return ierr;
78 }
79