Actual source code: ex82.c
2: static char help[] = "Partition a tiny grid using hierarchical partitioning.\n\n";
4: /*
5: Include "petscmat.h" so that we can use matrices. Note that this file
6: automatically includes:
7: petscsys.h - base PETSc routines petscvec.h - vectors
8: petscmat.h - matrices
9: petscis.h - index sets
10: petscviewer.h - viewers
11: */
12: #include <petscmat.h>
14: int main(int argc,char **args)
15: {
16: Mat A;
17: PetscMPIInt rank,size;
18: PetscInt *ia,*ja;
19: MatPartitioning part;
20: IS is,isn,isrows;
21: IS coarseparts,fineparts;
22: MPI_Comm comm;
24: PetscInitialize(&argc,&args,(char*)0,help);
25: comm = PETSC_COMM_WORLD;
26: MPI_Comm_size(comm,&size);
28: MPI_Comm_rank(comm,&rank);
30: PetscMalloc1(5,&ia);
31: PetscMalloc1(16,&ja);
32: if (rank == 0) {
33: ja[0] = 1; ja[1] = 4; ja[2] = 0; ja[3] = 2; ja[4] = 5; ja[5] = 1; ja[6] = 3; ja[7] = 6;
34: ja[8] = 2; ja[9] = 7;
35: ia[0] = 0; ia[1] = 2; ia[2] = 5; ia[3] = 8; ia[4] = 10;
36: } else if (rank == 1) {
37: ja[0] = 0; ja[1] = 5; ja[2] = 8; ja[3] = 1; ja[4] = 4; ja[5] = 6; ja[6] = 9; ja[7] = 2;
38: ja[8] = 5; ja[9] = 7; ja[10] = 10; ja[11] = 3; ja[12] = 6; ja[13] = 11;
39: ia[0] = 0; ia[1] = 3; ia[2] = 7; ia[3] = 11; ia[4] = 14;
40: } else if (rank == 2) {
41: ja[0] = 4; ja[1] = 9; ja[2] = 12; ja[3] = 5; ja[4] = 8; ja[5] = 10; ja[6] = 13; ja[7] = 6;
42: ja[8] = 9; ja[9] = 11; ja[10] = 14; ja[11] = 7; ja[12] = 10; ja[13] = 15;
43: ia[0] = 0; ia[1] = 3; ia[2] = 7; ia[3] = 11; ia[4] = 14;
44: } else {
45: ja[0] = 8; ja[1] = 13; ja[2] = 9; ja[3] = 12; ja[4] = 14; ja[5] = 10; ja[6] = 13; ja[7] = 15;
46: ja[8] = 11; ja[9] = 14;
47: ia[0] = 0; ia[1] = 2; ia[2] = 5; ia[3] = 8; ia[4] = 10;
48: }
49: MatCreateMPIAdj(comm,4,16,ia,ja,NULL,&A);
50: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
51: /*
52: Partition the graph of the matrix
53: */
54: MatPartitioningCreate(comm,&part);
55: MatPartitioningSetAdjacency(part,A);
56: MatPartitioningSetType(part,MATPARTITIONINGHIERARCH);
57: MatPartitioningHierarchicalSetNcoarseparts(part,2);
58: MatPartitioningHierarchicalSetNfineparts(part,2);
59: MatPartitioningSetFromOptions(part);
60: /* get new processor owner number of each vertex */
61: MatPartitioningApply(part,&is);
62: /* coarse parts */
63: MatPartitioningHierarchicalGetCoarseparts(part,&coarseparts);
64: ISView(coarseparts,PETSC_VIEWER_STDOUT_WORLD);
65: /* fine parts */
66: MatPartitioningHierarchicalGetFineparts(part,&fineparts);
67: ISView(fineparts,PETSC_VIEWER_STDOUT_WORLD);
68: /* partitioning */
69: ISView(is,PETSC_VIEWER_STDOUT_WORLD);
70: /* get new global number of each old global number */
71: ISPartitioningToNumbering(is,&isn);
72: ISView(isn,PETSC_VIEWER_STDOUT_WORLD);
73: ISBuildTwoSided(is,NULL,&isrows);
74: ISView(isrows,PETSC_VIEWER_STDOUT_WORLD);
75: ISDestroy(&is);
76: ISDestroy(&coarseparts);
77: ISDestroy(&fineparts);
78: ISDestroy(&isrows);
79: ISDestroy(&isn);
80: MatPartitioningDestroy(&part);
81: /*
82: Free work space. All PETSc objects should be destroyed when they
83: are no longer needed.
84: */
85: MatDestroy(&A);
86: PetscFinalize();
87: return 0;
88: }
90: /*TEST
92: test:
93: nsize: 4
94: requires: parmetis
95: TODO: tests cannot use parmetis because it produces different results on different machines
97: TEST*/