> On Apr 15, 2017, at 12:13 PM, Orxan Shibliyev <[email protected]> wrote:
>
> I modified ex11.c:
How did you modify it, what exactly did you change?
> Tests MatMeshToDual() in order to partition the unstructured grid provided in
> Petsc documentation, page 71. The resulting code is as follows but MatView()
> does not print entries of matrix, dual whereas in the original example it
> does.
What does MatView() show instead? How is the output different? Send as
attachments the "modified" example and the output from both.
> Why?
>
> static char help[] = "Tests MatMeshToDual()\n\n";
>
> /*T
> Concepts: Mat^mesh partitioning
> Processors: n
> T*/
>
> /*
> Include "petscmat.h" so that we can use matrices.
> automatically includes:
> petscsys.h - base PETSc routines petscvec.h - vectors
> petscmat.h - matrices
> petscis.h - index sets petscviewer.h - viewers
> */
> #include <petscmat.h>
>
> #undef __FUNCT__
> #define __FUNCT__ "main"
> int main(int argc,char **args)
> {
> Mat mesh,dual;
> PetscErrorCode ierr;
> PetscInt Nvertices = 4; /* total number of vertices */
> PetscInt ncells = 2; /* number cells on this process */
> PetscInt *ii,*jj;
> PetscMPIInt size,rank;
> MatPartitioning part;
> IS is;
>
> PetscInitialize(&argc,&args,(char*)0,help);
> ierr = MPI_Comm_size(MPI_COMM_WORLD,&size);CHKERRQ(ierr);
> if (size != 2) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"This example is
> for exactly two processes");
> ierr = MPI_Comm_rank(MPI_COMM_WORLD,&rank);CHKERRQ(ierr);
>
> ierr = PetscMalloc1(3,&ii);CHKERRQ(ierr);
> ierr = PetscMalloc1(3,&jj);CHKERRQ(ierr);
> if (rank == 0) {
> ii[0] = 0; ii[1] = 2; ii[2] = 3;
> jj[0] = 2; jj[1] = 3; jj[2] = 3;
> } else {
> ii[0] = 0; ii[1] = 1; ii[2] = 3;
> jj[0] = 0; jj[1] = 0; jj[2] = 1;
> }
> ierr =
> MatCreateMPIAdj(MPI_COMM_WORLD,ncells,Nvertices,ii,jj,NULL,&mesh);CHKERRQ(ierr);
> ierr = MatMeshToCellGraph(mesh,2,&dual);CHKERRQ(ierr);
> ierr = MatView(dual,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
>
> ierr = MatPartitioningCreate(MPI_COMM_WORLD,&part);CHKERRQ(ierr);
> ierr = MatPartitioningSetAdjacency(part,dual);CHKERRQ(ierr);
> ierr = MatPartitioningSetFromOptions(part);CHKERRQ(ierr);
> ierr = MatPartitioningApply(part,&is);CHKERRQ(ierr);
> ierr = ISView(is,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
> ierr = ISDestroy(&is);CHKERRQ(ierr);
> ierr = MatPartitioningDestroy(&part);CHKERRQ(ierr);
>
> ierr = MatDestroy(&mesh);CHKERRQ(ierr);
> ierr = MatDestroy(&dual);CHKERRQ(ierr);
> ierr = PetscFinalize();
> return 0;
> }
