xref: /petsc/src/mat/tests/ex59.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
1*c4762a1bSJed Brown 
2*c4762a1bSJed Brown static char help[] = "Tests MatCreateSubmatrix() in parallel.";
3*c4762a1bSJed Brown 
4*c4762a1bSJed Brown #include <petscmat.h>
5*c4762a1bSJed Brown 
6*c4762a1bSJed Brown int main(int argc,char **args)
7*c4762a1bSJed Brown {
8*c4762a1bSJed Brown   Mat            C,A;
9*c4762a1bSJed Brown   PetscInt       i,j,m = 3,n = 2,rstart,rend;
10*c4762a1bSJed Brown   PetscMPIInt    size,rank;
11*c4762a1bSJed Brown   PetscErrorCode ierr;
12*c4762a1bSJed Brown   PetscScalar    v;
13*c4762a1bSJed Brown   IS             isrow,iscol;
14*c4762a1bSJed Brown 
15*c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
16*c4762a1bSJed Brown   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
17*c4762a1bSJed Brown   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
18*c4762a1bSJed Brown   n    = 2*size;
19*c4762a1bSJed Brown 
20*c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD,&C);CHKERRQ(ierr);
21*c4762a1bSJed Brown   ierr = MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);CHKERRQ(ierr);
22*c4762a1bSJed Brown   ierr = MatSetFromOptions(C);CHKERRQ(ierr);
23*c4762a1bSJed Brown   ierr = MatSetUp(C);CHKERRQ(ierr);
24*c4762a1bSJed Brown 
25*c4762a1bSJed Brown   /*
26*c4762a1bSJed Brown         This is JUST to generate a nice test matrix, all processors fill up
27*c4762a1bSJed Brown     the entire matrix. This is not something one would ever do in practice.
28*c4762a1bSJed Brown   */
29*c4762a1bSJed Brown   ierr = MatGetOwnershipRange(C,&rstart,&rend);CHKERRQ(ierr);
30*c4762a1bSJed Brown   for (i=rstart; i<rend; i++) {
31*c4762a1bSJed Brown     for (j=0; j<m*n; j++) {
32*c4762a1bSJed Brown       v    = i + j + 1;
33*c4762a1bSJed Brown       ierr = MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr);
34*c4762a1bSJed Brown     }
35*c4762a1bSJed Brown   }
36*c4762a1bSJed Brown 
37*c4762a1bSJed Brown   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
38*c4762a1bSJed Brown   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
39*c4762a1bSJed Brown   ierr = PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_COMMON);CHKERRQ(ierr);
40*c4762a1bSJed Brown   ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
41*c4762a1bSJed Brown 
42*c4762a1bSJed Brown   /*
43*c4762a1bSJed Brown      Generate a new matrix consisting of every second row and column of
44*c4762a1bSJed Brown    the original matrix
45*c4762a1bSJed Brown   */
46*c4762a1bSJed Brown   ierr = MatGetOwnershipRange(C,&rstart,&rend);CHKERRQ(ierr);
47*c4762a1bSJed Brown   /* Create parallel IS with the rows we want on THIS processor */
48*c4762a1bSJed Brown   ierr = ISCreateStride(PETSC_COMM_WORLD,(rend-rstart)/2,rstart,2,&isrow);CHKERRQ(ierr);
49*c4762a1bSJed Brown   /* Create parallel IS with the rows we want on THIS processor (same as rows for now) */
50*c4762a1bSJed Brown   ierr = ISCreateStride(PETSC_COMM_WORLD,(rend-rstart)/2,rstart,2,&iscol);CHKERRQ(ierr);
51*c4762a1bSJed Brown 
52*c4762a1bSJed Brown   ierr = MatCreateSubMatrix(C,isrow,iscol,MAT_INITIAL_MATRIX,&A);CHKERRQ(ierr);
53*c4762a1bSJed Brown   ierr = MatCreateSubMatrix(C,isrow,iscol,MAT_REUSE_MATRIX,&A);CHKERRQ(ierr);
54*c4762a1bSJed Brown   ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
55*c4762a1bSJed Brown 
56*c4762a1bSJed Brown   ierr = ISDestroy(&isrow);CHKERRQ(ierr);
57*c4762a1bSJed Brown   ierr = ISDestroy(&iscol);CHKERRQ(ierr);
58*c4762a1bSJed Brown   ierr = MatDestroy(&A);CHKERRQ(ierr);
59*c4762a1bSJed Brown   ierr = MatDestroy(&C);CHKERRQ(ierr);
60*c4762a1bSJed Brown   ierr = PetscFinalize();
61*c4762a1bSJed Brown   return ierr;
62*c4762a1bSJed Brown }
63*c4762a1bSJed Brown 
64*c4762a1bSJed Brown 
65*c4762a1bSJed Brown /*TEST
66*c4762a1bSJed Brown 
67*c4762a1bSJed Brown    test:
68*c4762a1bSJed Brown 
69*c4762a1bSJed Brown    test:
70*c4762a1bSJed Brown       suffix: 2
71*c4762a1bSJed Brown       nsize: 3
72*c4762a1bSJed Brown 
73*c4762a1bSJed Brown    test:
74*c4762a1bSJed Brown       suffix: 2_baij
75*c4762a1bSJed Brown       nsize: 3
76*c4762a1bSJed Brown       args: -mat_type baij
77*c4762a1bSJed Brown 
78*c4762a1bSJed Brown    test:
79*c4762a1bSJed Brown       suffix: 2_sbaij
80*c4762a1bSJed Brown       nsize: 3
81*c4762a1bSJed Brown       args: -mat_type sbaij
82*c4762a1bSJed Brown 
83*c4762a1bSJed Brown    test:
84*c4762a1bSJed Brown       suffix: baij
85*c4762a1bSJed Brown       args: -mat_type baij
86*c4762a1bSJed Brown       output_file: output/ex59_1_baij.out
87*c4762a1bSJed Brown 
88*c4762a1bSJed Brown    test:
89*c4762a1bSJed Brown       suffix: sbaij
90*c4762a1bSJed Brown       args: -mat_type sbaij
91*c4762a1bSJed Brown       output_file: output/ex59_1_sbaij.out
92*c4762a1bSJed Brown 
93*c4762a1bSJed Brown TEST*/
94