xref: /petsc/src/mat/tests/ex212.c (revision a2fddd78f770fa4fc19a8af67e65be331f27d92b)
1 static char help[] = "Test MatCreateSubMatrix with -mat_type nest and block sizes.\n";
2 
3 #include <petscmat.h>
4 
5 int main(int argc, char **argv)
6 {
7   Mat                    A, B, C, mats[6];
8   IS                     rows[2];
9   ISLocalToGlobalMapping cmap, rmap;
10   const PetscInt         indices[3] = {0, 1, 2};
11   PetscInt               i;
12   PetscMPIInt            size;
13   PetscErrorCode         ierr;
14 
15   ierr = PetscInitialize(&argc,&argv,NULL,help); if (ierr) return ierr;
16   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRMPI(ierr);
17   if (size > 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_ARG_WRONG,"Only coded for one process");
18   ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
19   ierr = MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,2,1);CHKERRQ(ierr);
20   ierr = MatSetBlockSizes(A,2,1);CHKERRQ(ierr);
21   ierr = MatSetType(A,MATAIJ);CHKERRQ(ierr);
22   ierr = ISLocalToGlobalMappingCreate(PETSC_COMM_WORLD,2,1,indices,PETSC_COPY_VALUES,&rmap);CHKERRQ(ierr);
23   ierr = ISLocalToGlobalMappingCreate(PETSC_COMM_WORLD,1,1,indices,PETSC_COPY_VALUES,&cmap);CHKERRQ(ierr);
24   ierr = MatSetLocalToGlobalMapping(A,rmap,cmap);CHKERRQ(ierr);
25   ierr = ISLocalToGlobalMappingDestroy(&rmap);CHKERRQ(ierr);
26   ierr = ISLocalToGlobalMappingDestroy(&cmap);CHKERRQ(ierr);
27   ierr = ISLocalToGlobalMappingCreate(PETSC_COMM_WORLD,1,2,indices,PETSC_COPY_VALUES,&rmap);CHKERRQ(ierr);
28   ierr = ISLocalToGlobalMappingCreate(PETSC_COMM_WORLD,1,3,indices,PETSC_COPY_VALUES,&cmap);CHKERRQ(ierr);
29   ierr = MatCreate(PETSC_COMM_WORLD,&B);CHKERRQ(ierr);
30   ierr = MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,2,3);CHKERRQ(ierr);
31   ierr = MatSetBlockSizes(B,1,1);CHKERRQ(ierr);
32   ierr = MatSetType(B,MATAIJ);CHKERRQ(ierr);
33   ierr = MatSetLocalToGlobalMapping(B,rmap,cmap);CHKERRQ(ierr);
34   ierr = ISLocalToGlobalMappingDestroy(&rmap);CHKERRQ(ierr);
35   ierr = ISLocalToGlobalMappingDestroy(&cmap);CHKERRQ(ierr);
36   ierr = MatSetUp(A);CHKERRQ(ierr);
37   ierr = MatSetUp(B);CHKERRQ(ierr);
38   mats[0] = A;
39   mats[1] = B;
40   mats[2] = A;
41   mats[3] = NULL;
42   mats[4] = B;
43   mats[5] = A;
44   ierr = MatCreateNest(PETSC_COMM_WORLD,2,NULL,3,NULL,mats,&C);CHKERRQ(ierr);
45   ierr = MatSetUp(C);CHKERRQ(ierr);
46   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
47   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
48   ierr = MatView(C,NULL);CHKERRQ(ierr);
49   ierr = MatNestGetISs(C,rows,NULL);CHKERRQ(ierr);
50   for (i=0; i<2; i++) {
51     Mat      submat;
52     IS       cols[3];
53     PetscInt j;
54     ierr = ISView(rows[i],NULL);CHKERRQ(ierr);
55     ierr = MatCreateSubMatrix(C,rows[i],NULL,MAT_INITIAL_MATRIX,&submat);CHKERRQ(ierr);
56     ierr = MatView(submat,NULL);CHKERRQ(ierr);
57     ierr = MatNestGetISs(submat,NULL,cols);CHKERRQ(ierr);
58     for (j=0; j<3; j++) {
59       ierr = ISView(cols[j],NULL);CHKERRQ(ierr);
60     }
61     ierr = MatDestroy(&submat);CHKERRQ(ierr);
62   }
63   ierr = MatDestroy(&C);CHKERRQ(ierr);
64   ierr = MatDestroy(&B);CHKERRQ(ierr);
65   ierr = MatDestroy(&A);CHKERRQ(ierr);
66   ierr = PetscFinalize();
67   return ierr;
68 }
69 
70 /*TEST
71 
72     test:
73 
74 TEST*/
75