xref: /petsc/src/mat/tests/ex101.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
1 static char help[] = "Testing PtAP for SeqMAIJ matrix, P, with SeqAIJ matrix, A.\n\n";
2 
3 #include <petscmat.h>
4 
5 int main(int argc,char **argv)
6 {
7   Mat            pA,P,aijP;
8   PetscScalar    pa[]={1.,-1.,0.,0.,1.,-1.,0.,0.,1.};
9   PetscInt       i,pij[]={0,1,2};
10   PetscInt       aij[3][3]={{0,1,2},{3,4,5},{6,7,8}};
11   Mat            A,mC,C;
12   PetscScalar    one=1.;
13   PetscErrorCode ierr;
14   PetscMPIInt    size;
15 
16   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
17   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
18   if (size != 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"This is a uniprocessor example only!");
19 
20   /* Create MAIJ matrix, P */
21   ierr = MatCreate(PETSC_COMM_SELF,&pA);CHKERRQ(ierr);
22   ierr = MatSetSizes(pA,3,3,3,3);CHKERRQ(ierr);
23   ierr = MatSetType(pA,MATSEQAIJ);CHKERRQ(ierr);
24   ierr = MatSetUp(pA);CHKERRQ(ierr);
25   ierr = MatSetOption(pA,MAT_IGNORE_ZERO_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
26   ierr = MatSetValues(pA,3,pij,3,pij,pa,ADD_VALUES);CHKERRQ(ierr);
27   ierr = MatAssemblyBegin(pA,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
28   ierr = MatAssemblyEnd(pA,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
29   ierr = MatCreateMAIJ(pA,3,&P);CHKERRQ(ierr);
30   ierr = MatDestroy(&pA);CHKERRQ(ierr);
31 
32   /* Create AIJ equivalent matrix, aijP, for comparison testing */
33   ierr = MatConvert(P,MATSEQAIJ,MAT_INITIAL_MATRIX,&aijP);CHKERRQ(ierr);
34 
35   /* Create AIJ matrix, A */
36   ierr = MatCreate(PETSC_COMM_SELF,&A);CHKERRQ(ierr);
37   ierr = MatSetSizes(A,9,9,9,9);CHKERRQ(ierr);
38   ierr = MatSetType(A,MATSEQAIJ);CHKERRQ(ierr);
39   ierr = MatSetUp(A);CHKERRQ(ierr);
40   ierr = MatSetOption(A,MAT_IGNORE_ZERO_ENTRIES,PETSC_TRUE);CHKERRQ(ierr);
41   ierr = MatSetValues(A,3,aij[0],3,aij[0],pa,ADD_VALUES);CHKERRQ(ierr);
42   ierr = MatSetValues(A,3,aij[1],3,aij[1],pa,ADD_VALUES);CHKERRQ(ierr);
43   ierr = MatSetValues(A,3,aij[2],3,aij[2],pa,ADD_VALUES);CHKERRQ(ierr);
44   for (i=0; i<9; i++) {
45     ierr = MatSetValue(A,i,i,one,ADD_VALUES);CHKERRQ(ierr);
46   }
47   ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
48   ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
49 
50   /* Perform PtAP_SeqAIJ_SeqMAIJ */
51   ierr = MatPtAP(A,P,MAT_INITIAL_MATRIX,1.,&mC);CHKERRQ(ierr);
52   ierr = MatPtAP(A,P,MAT_REUSE_MATRIX,1.,&mC);CHKERRQ(ierr);
53   ierr = MatView(mC,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
54 
55   /* Perform PtAP_SeqAIJ_SeqAIJ for comparison testing */
56   ierr = MatPtAP(A,aijP,MAT_INITIAL_MATRIX,1.,&C);CHKERRQ(ierr);
57   ierr = MatView(C,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
58 
59   /* Check mC = C */
60   ierr = MatAXPY(C,-1.0,mC,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr);
61   /* Note: We should be able to use SAME_NONZERO_PATTERN on the line above, */
62   /*       but don't because this flag doesn't assist testing. */
63   ierr = MatView(C,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
64 
65   /* Cleanup */
66   ierr = MatDestroy(&P);CHKERRQ(ierr);
67   ierr = MatDestroy(&aijP);CHKERRQ(ierr);
68   ierr = MatDestroy(&A);CHKERRQ(ierr);
69   ierr = MatDestroy(&C);CHKERRQ(ierr);
70   ierr = MatDestroy(&mC);CHKERRQ(ierr);
71   ierr = PetscFinalize();
72   return ierr;
73 }
74 
75 
76 /*TEST
77 
78    test:
79       output_file: output/ex101.out
80 
81 TEST*/
82