xref: /petsc/src/mat/tests/ex213.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
1*c4762a1bSJed Brown 
2*c4762a1bSJed Brown static char help[] = "Tests MatMPIBAIJSetPreallocationCSR()\n\n";
3*c4762a1bSJed Brown 
4*c4762a1bSJed Brown /*T
5*c4762a1bSJed Brown    Concepts: partitioning
6*c4762a1bSJed Brown    Processors: 4
7*c4762a1bSJed Brown T*/
8*c4762a1bSJed Brown 
9*c4762a1bSJed Brown /*
10*c4762a1bSJed Brown   Include "petscmat.h" so that we can use matrices.  Note that this file
11*c4762a1bSJed Brown   automatically includes:
12*c4762a1bSJed Brown      petscsys.h       - base PETSc routines   petscvec.h - vectors
13*c4762a1bSJed Brown      petscmat.h - matrices
14*c4762a1bSJed Brown      petscis.h     - index sets
15*c4762a1bSJed Brown      petscviewer.h - viewers
16*c4762a1bSJed Brown */
17*c4762a1bSJed Brown #include <petscmat.h>
18*c4762a1bSJed Brown 
19*c4762a1bSJed Brown int main(int argc,char **args)
20*c4762a1bSJed Brown {
21*c4762a1bSJed Brown   Mat            A;
22*c4762a1bSJed Brown   PetscInt       *ia,*ja, bs = 2;
23*c4762a1bSJed Brown   PetscInt       N = 9, n;
24*c4762a1bSJed Brown   PetscInt       rstart, rend, row, col;
25*c4762a1bSJed Brown   PetscInt       i;
26*c4762a1bSJed Brown   PetscErrorCode ierr;
27*c4762a1bSJed Brown   PetscMPIInt    rank,size;
28*c4762a1bSJed Brown   Vec            v;
29*c4762a1bSJed Brown 
30*c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
31*c4762a1bSJed Brown   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
32*c4762a1bSJed Brown   if ( size > 4 ) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Can only use at most 4 processors.");
33*c4762a1bSJed Brown   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
34*c4762a1bSJed Brown 
35*c4762a1bSJed Brown   /* Get a partition range based on the vector size */
36*c4762a1bSJed Brown   ierr = VecCreateMPI(PETSC_COMM_WORLD, PETSC_DECIDE, N, &v);CHKERRQ(ierr);
37*c4762a1bSJed Brown   ierr = VecGetLocalSize(v, &n);CHKERRQ(ierr);
38*c4762a1bSJed Brown   ierr = VecGetOwnershipRange(v, &rstart, &rend);CHKERRQ(ierr);
39*c4762a1bSJed Brown   ierr = VecDestroy(&v);CHKERRQ(ierr);
40*c4762a1bSJed Brown 
41*c4762a1bSJed Brown   ierr = PetscMalloc1(n+1,&ia);CHKERRQ(ierr);
42*c4762a1bSJed Brown   ierr = PetscMalloc1(3*n,&ja);CHKERRQ(ierr);
43*c4762a1bSJed Brown 
44*c4762a1bSJed Brown   /* Construct a tri-diagonal CSR indexing */
45*c4762a1bSJed Brown   i = 1;
46*c4762a1bSJed Brown   ia[0] = 0;
47*c4762a1bSJed Brown   for ( row = rstart; row < rend; row++ )
48*c4762a1bSJed Brown   {
49*c4762a1bSJed Brown     ia[i] = ia[i-1];
50*c4762a1bSJed Brown 
51*c4762a1bSJed Brown     /* diagonal */
52*c4762a1bSJed Brown     col = row;
53*c4762a1bSJed Brown     {
54*c4762a1bSJed Brown       ja[ia[i]] = col;
55*c4762a1bSJed Brown       ia[i]++;
56*c4762a1bSJed Brown     }
57*c4762a1bSJed Brown 
58*c4762a1bSJed Brown     /* lower diagonal */
59*c4762a1bSJed Brown     col = row-1;
60*c4762a1bSJed Brown     if (col >= 0)
61*c4762a1bSJed Brown     {
62*c4762a1bSJed Brown       ja[ia[i]] = col;
63*c4762a1bSJed Brown       ia[i]++;
64*c4762a1bSJed Brown     }
65*c4762a1bSJed Brown 
66*c4762a1bSJed Brown     /* upper diagonal */
67*c4762a1bSJed Brown     col = row+1;
68*c4762a1bSJed Brown     if (col < N )
69*c4762a1bSJed Brown     {
70*c4762a1bSJed Brown       ja[ia[i]] = col;
71*c4762a1bSJed Brown       ia[i]++;
72*c4762a1bSJed Brown     }
73*c4762a1bSJed Brown     i++;
74*c4762a1bSJed Brown   }
75*c4762a1bSJed Brown 
76*c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD, &A);CHKERRQ(ierr);
77*c4762a1bSJed Brown   ierr = MatSetSizes(A, n, n, PETSC_DETERMINE, PETSC_DETERMINE);CHKERRQ(ierr);
78*c4762a1bSJed Brown   ierr = MatSetType(A,MATMPIAIJ);CHKERRQ(ierr);
79*c4762a1bSJed Brown   ierr = MatMPIAIJSetPreallocationCSR(A, ia, ja, NULL);CHKERRQ(ierr);
80*c4762a1bSJed Brown   ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
81*c4762a1bSJed Brown   ierr = MatDestroy(&A);CHKERRQ(ierr);
82*c4762a1bSJed Brown 
83*c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD, &A);CHKERRQ(ierr);
84*c4762a1bSJed Brown   ierr = MatSetSizes(A, bs*n, bs*n, PETSC_DETERMINE, PETSC_DETERMINE);CHKERRQ(ierr);
85*c4762a1bSJed Brown   ierr = MatSetType(A,MATMPIBAIJ);CHKERRQ(ierr);
86*c4762a1bSJed Brown   ierr = MatMPIBAIJSetPreallocationCSR(A, bs, ia, ja, NULL);CHKERRQ(ierr);
87*c4762a1bSJed Brown   ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
88*c4762a1bSJed Brown   ierr = MatDestroy(&A);CHKERRQ(ierr);
89*c4762a1bSJed Brown 
90*c4762a1bSJed Brown   ierr = PetscFree(ia);CHKERRQ(ierr);
91*c4762a1bSJed Brown   ierr = PetscFree(ja);CHKERRQ(ierr);
92*c4762a1bSJed Brown   ierr = PetscFinalize();
93*c4762a1bSJed Brown   return ierr;
94*c4762a1bSJed Brown }
95*c4762a1bSJed Brown 
96*c4762a1bSJed Brown /*TEST
97*c4762a1bSJed Brown 
98*c4762a1bSJed Brown     test:
99*c4762a1bSJed Brown       nsize: 4
100*c4762a1bSJed Brown 
101*c4762a1bSJed Brown TEST*/
102*c4762a1bSJed Brown 
103