xref: /petsc/src/mat/tests/ex213.c (revision 5f80ce2ab25dff0f4601e710601cbbcecf323266)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests MatMPIBAIJSetPreallocationCSR()\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown /*T
5c4762a1bSJed Brown    Concepts: partitioning
6c4762a1bSJed Brown    Processors: 4
7c4762a1bSJed Brown T*/
8c4762a1bSJed Brown 
9c4762a1bSJed Brown /*
10c4762a1bSJed Brown   Include "petscmat.h" so that we can use matrices.  Note that this file
11c4762a1bSJed Brown   automatically includes:
12c4762a1bSJed Brown      petscsys.h       - base PETSc routines   petscvec.h - vectors
13c4762a1bSJed Brown      petscmat.h - matrices
14c4762a1bSJed Brown      petscis.h     - index sets
15c4762a1bSJed Brown      petscviewer.h - viewers
16c4762a1bSJed Brown */
17c4762a1bSJed Brown #include <petscmat.h>
18c4762a1bSJed Brown 
19c4762a1bSJed Brown int main(int argc,char **args)
20c4762a1bSJed Brown {
21c4762a1bSJed Brown   Mat            A;
22c4762a1bSJed Brown   PetscInt       *ia,*ja, bs = 2;
23c4762a1bSJed Brown   PetscInt       N = 9, n;
24c4762a1bSJed Brown   PetscInt       rstart, rend, row, col;
25c4762a1bSJed Brown   PetscInt       i;
26c4762a1bSJed Brown   PetscErrorCode ierr;
27c4762a1bSJed Brown   PetscMPIInt    rank,size;
28c4762a1bSJed Brown   Vec            v;
29c4762a1bSJed Brown 
30c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
31*5f80ce2aSJacob Faibussowitsch   CHKERRMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
322c71b3e2SJacob Faibussowitsch   PetscCheckFalse(size > 4,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Can only use at most 4 processors.");
33*5f80ce2aSJacob Faibussowitsch   CHKERRMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
34c4762a1bSJed Brown 
35c4762a1bSJed Brown   /* Get a partition range based on the vector size */
36*5f80ce2aSJacob Faibussowitsch   CHKERRQ(VecCreateMPI(PETSC_COMM_WORLD, PETSC_DECIDE, N, &v));
37*5f80ce2aSJacob Faibussowitsch   CHKERRQ(VecGetLocalSize(v, &n));
38*5f80ce2aSJacob Faibussowitsch   CHKERRQ(VecGetOwnershipRange(v, &rstart, &rend));
39*5f80ce2aSJacob Faibussowitsch   CHKERRQ(VecDestroy(&v));
40c4762a1bSJed Brown 
41*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscMalloc1(n+1,&ia));
42*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscMalloc1(3*n,&ja));
43c4762a1bSJed Brown 
44c4762a1bSJed Brown   /* Construct a tri-diagonal CSR indexing */
45c4762a1bSJed Brown   i = 1;
46c4762a1bSJed Brown   ia[0] = 0;
47c4762a1bSJed Brown   for (row = rstart; row < rend; row++)
48c4762a1bSJed Brown   {
49c4762a1bSJed Brown     ia[i] = ia[i-1];
50c4762a1bSJed Brown 
51c4762a1bSJed Brown     /* diagonal */
52c4762a1bSJed Brown     col = row;
53c4762a1bSJed Brown     {
54c4762a1bSJed Brown       ja[ia[i]] = col;
55c4762a1bSJed Brown       ia[i]++;
56c4762a1bSJed Brown     }
57c4762a1bSJed Brown 
58c4762a1bSJed Brown     /* lower diagonal */
59c4762a1bSJed Brown     col = row-1;
60c4762a1bSJed Brown     if (col >= 0)
61c4762a1bSJed Brown     {
62c4762a1bSJed Brown       ja[ia[i]] = col;
63c4762a1bSJed Brown       ia[i]++;
64c4762a1bSJed Brown     }
65c4762a1bSJed Brown 
66c4762a1bSJed Brown     /* upper diagonal */
67c4762a1bSJed Brown     col = row+1;
68c4762a1bSJed Brown     if (col < N)
69c4762a1bSJed Brown     {
70c4762a1bSJed Brown       ja[ia[i]] = col;
71c4762a1bSJed Brown       ia[i]++;
72c4762a1bSJed Brown     }
73c4762a1bSJed Brown     i++;
74c4762a1bSJed Brown   }
75c4762a1bSJed Brown 
76*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatCreate(PETSC_COMM_WORLD, &A));
77*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetSizes(A, n, n, PETSC_DETERMINE, PETSC_DETERMINE));
78*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetType(A,MATMPIAIJ));
79*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatMPIAIJSetPreallocationCSR(A, ia, ja, NULL));
80*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
81*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatDestroy(&A));
82c4762a1bSJed Brown 
83*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatCreate(PETSC_COMM_WORLD, &A));
84*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetSizes(A, bs*n, bs*n, PETSC_DETERMINE, PETSC_DETERMINE));
85*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetType(A,MATMPIBAIJ));
86*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatMPIBAIJSetPreallocationCSR(A, bs, ia, ja, NULL));
87*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
88*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatDestroy(&A));
89c4762a1bSJed Brown 
90*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscFree(ia));
91*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscFree(ja));
92c4762a1bSJed Brown   ierr = PetscFinalize();
93c4762a1bSJed Brown   return ierr;
94c4762a1bSJed Brown }
95c4762a1bSJed Brown 
96c4762a1bSJed Brown /*TEST
97c4762a1bSJed Brown 
98c4762a1bSJed Brown     test:
99c4762a1bSJed Brown       nsize: 4
100c4762a1bSJed Brown 
101c4762a1bSJed Brown TEST*/
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