xref: /petsc/src/mat/tests/ex194.c (revision 5f80ce2ab25dff0f4601e710601cbbcecf323266)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests MatCreateSubmatrix() with certain entire rows of matrix, modified from ex181.c.";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown #include <petscmat.h>
5c4762a1bSJed Brown 
6c4762a1bSJed Brown int main(int argc,char **args)
7c4762a1bSJed Brown {
8c4762a1bSJed Brown   Mat            C,A;
9c4762a1bSJed Brown   PetscInt       i,j,m = 3,n = 2,rstart,rend,cstart,cend;
10c4762a1bSJed Brown   PetscMPIInt    size,rank;
11c4762a1bSJed Brown   PetscErrorCode ierr;
12c4762a1bSJed Brown   PetscScalar    v;
13c4762a1bSJed Brown   IS             isrow,iscol;
14c4762a1bSJed Brown 
15c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
16*5f80ce2aSJacob Faibussowitsch   CHKERRMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
17*5f80ce2aSJacob Faibussowitsch   CHKERRMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
18c4762a1bSJed Brown   n    = 2*size;
19c4762a1bSJed Brown 
20*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatCreate(PETSC_COMM_WORLD,&C));
21*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n));
22*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetFromOptions(C));
23*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetUp(C));
24c4762a1bSJed Brown 
25c4762a1bSJed Brown   /*
26c4762a1bSJed Brown         This is JUST to generate a nice test matrix, all processors fill up
27c4762a1bSJed Brown     the entire matrix. This is not something one would ever do in practice.
28c4762a1bSJed Brown   */
29*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatGetOwnershipRange(C,&rstart,&rend));
30c4762a1bSJed Brown   for (i=rstart; i<rend; i++) {
31c4762a1bSJed Brown     for (j=0; j<m*n; j++) {
32c4762a1bSJed Brown       v    = i + j + 1;
33*5f80ce2aSJacob Faibussowitsch       CHKERRQ(MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES));
34c4762a1bSJed Brown     }
35c4762a1bSJed Brown   }
36*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY));
37*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY));
38*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_COMMON));
39*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatView(C,PETSC_VIEWER_STDOUT_WORLD));
40*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
41c4762a1bSJed Brown 
42c4762a1bSJed Brown   /*
43c4762a1bSJed Brown      Generate a new matrix consisting every column of the original matrix
44c4762a1bSJed Brown   */
45*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatGetOwnershipRange(C,&rstart,&rend));
46*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatGetOwnershipRangeColumn(C,&cstart,&cend));
47c4762a1bSJed Brown 
48*5f80ce2aSJacob Faibussowitsch   CHKERRQ(ISCreateStride(PETSC_COMM_WORLD,rend-rstart > 0 ? rend-rstart-1 : 0,rstart,1,&isrow));
49*5f80ce2aSJacob Faibussowitsch   CHKERRQ(ISCreateStride(PETSC_COMM_WORLD,cend-cstart,cstart,1,&iscol));
50*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatCreateSubMatrix(C,isrow,NULL,MAT_INITIAL_MATRIX,&A));
51c4762a1bSJed Brown 
52c4762a1bSJed Brown   /* Change C to test the case MAT_REUSE_MATRIX */
53dd400576SPatrick Sanan   if (rank == 0) {
54c4762a1bSJed Brown     i = 0; j = 0; v = 100;
55*5f80ce2aSJacob Faibussowitsch     CHKERRQ(MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES));
56c4762a1bSJed Brown   }
57*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY));
58*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY));
59c4762a1bSJed Brown 
60*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatCreateSubMatrix(C,isrow,NULL,MAT_REUSE_MATRIX,&A));
61*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_COMMON));
62*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
63*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
64c4762a1bSJed Brown 
65*5f80ce2aSJacob Faibussowitsch   CHKERRQ(ISDestroy(&isrow));
66*5f80ce2aSJacob Faibussowitsch   CHKERRQ(ISDestroy(&iscol));
67*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatDestroy(&A));
68*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatDestroy(&C));
69c4762a1bSJed Brown   ierr = PetscFinalize();
70c4762a1bSJed Brown   return ierr;
71c4762a1bSJed Brown }
72c4762a1bSJed Brown 
73c4762a1bSJed Brown /*TEST
74c4762a1bSJed Brown 
75c4762a1bSJed Brown    test:
76c4762a1bSJed Brown       nsize: 2
77c4762a1bSJed Brown 
78c4762a1bSJed Brown TEST*/
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