xref: /petsc/src/dm/impls/plex/tests/ex28.c (revision 732aec7a18f2199fb53bb9a2f3aef439a834ce31)
1c4762a1bSJed Brown static char help[] = "Compare parallel partitioning strategies using matrix graphs\n\n";
2c4762a1bSJed Brown 
3c4762a1bSJed Brown #include <petscmat.h>
4c4762a1bSJed Brown 
main(int argc,char ** args)5d71ae5a4SJacob Faibussowitsch int main(int argc, char **args)
6d71ae5a4SJacob Faibussowitsch {
7c4762a1bSJed Brown   MatPartitioning part;
8c4762a1bSJed Brown   IS              partis;
9c4762a1bSJed Brown   Mat             A       = NULL;
10c4762a1bSJed Brown   PetscInt        max     = -1;
11c4762a1bSJed Brown   PetscInt        min     = -1;
12c4762a1bSJed Brown   PetscReal       balance = 0.0;
13c4762a1bSJed Brown   const PetscInt *ranges  = NULL;
14c4762a1bSJed Brown   char            filein[PETSC_MAX_PATH_LEN];
15c4762a1bSJed Brown   MPI_Comm        comm;
16c4762a1bSJed Brown   PetscMPIInt     size;
17c4762a1bSJed Brown   PetscInt        p;
18c4762a1bSJed Brown   PetscBool       flg;
19c4762a1bSJed Brown 
20c4762a1bSJed Brown   /*load matrix*/
21327415f7SBarry Smith   PetscFunctionBeginUser;
22*c8025a54SPierre Jolivet   PetscCall(PetscInitialize(&argc, &args, NULL, help));
23c4762a1bSJed Brown   comm = PETSC_COMM_WORLD;
249566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_size(comm, &size));
259566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetString(NULL, NULL, "-fin", filein, sizeof(filein), &flg));
26c4762a1bSJed Brown   if (flg) {
27c4762a1bSJed Brown     PetscViewer view;
289566063dSJacob Faibussowitsch     PetscCall(PetscViewerBinaryOpen(comm, filein, FILE_MODE_READ, &view));
299566063dSJacob Faibussowitsch     PetscCall(MatCreate(comm, &A));
309566063dSJacob Faibussowitsch     PetscCall(MatLoad(A, view));
319566063dSJacob Faibussowitsch     PetscCall(PetscViewerDestroy(&view));
32c4762a1bSJed Brown   }
33c4762a1bSJed Brown 
34c4762a1bSJed Brown   /*partition matrix*/
359566063dSJacob Faibussowitsch   PetscCall(MatPartitioningCreate(comm, &part));
369566063dSJacob Faibussowitsch   PetscCall(MatPartitioningSetAdjacency(part, A));
379566063dSJacob Faibussowitsch   PetscCall(MatPartitioningSetFromOptions(part));
389566063dSJacob Faibussowitsch   PetscCall(MatPartitioningApply(part, &partis));
399566063dSJacob Faibussowitsch   PetscCall(MatGetOwnershipRanges(A, &ranges));
409566063dSJacob Faibussowitsch   PetscCall(MatGetSize(A, &min, NULL));
41c4762a1bSJed Brown   for (p = 0; p < size; ++p) {
42c4762a1bSJed Brown     const PetscInt partsize = ranges[p + 1] - ranges[p];
43c4762a1bSJed Brown 
44c4762a1bSJed Brown     max = PetscMax(max, partsize);
45c4762a1bSJed Brown     min = PetscMin(min, partsize);
46c4762a1bSJed Brown   }
47c4762a1bSJed Brown   balance = ((PetscReal)max) / min;
489566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(comm, "ranges: "));
49c4762a1bSJed Brown   for (p = 0; p <= size; ++p) {
509566063dSJacob Faibussowitsch     if (p > 0) PetscCall(PetscPrintf(comm, ", "));
5163a3b9bcSJacob Faibussowitsch     PetscCall(PetscPrintf(comm, "%" PetscInt_FMT, ranges[p]));
52c4762a1bSJed Brown   }
539566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(comm, "\n"));
549566063dSJacob Faibussowitsch   PetscCall(PetscPrintf(comm, "max:%.0lf min:%.0lf balance:%.11lf\n", (double)max, (double)min, (double)balance));
559566063dSJacob Faibussowitsch   PetscCall(PetscObjectViewFromOptions((PetscObject)partis, NULL, "-partition_view"));
569566063dSJacob Faibussowitsch   PetscCall(MatPartitioningDestroy(&part));
579566063dSJacob Faibussowitsch   PetscCall(ISDestroy(&partis));
589566063dSJacob Faibussowitsch   PetscCall(MatDestroy(&A));
599566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
60b122ec5aSJacob Faibussowitsch   return 0;
61c4762a1bSJed Brown }
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