/* -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.

  Detected bug in DMCreateMatrix() for skinny domains with periodic boundary conditions in overestimating nonzero preallocation

  Creation Date : 08-12-2016

  Last Modified : Thu 08 Dec 2016 10:46:02 AM CET

  Created By : Davide Monsorno

_._._._._._._._._._._._._._._._._._._._._.*/

#include <petscdmda.h>

int main(int argc, char *argv[])
{
  PetscInt       nx = 2;
  PetscInt       ny = 2;
  PetscInt       nz = 128;
  DM             da;
  Mat            A;

  PetscCall(PetscInitialize(&argc,&argv,NULL,NULL));
  PetscCall(DMDACreate3d(PETSC_COMM_WORLD,DM_BOUNDARY_PERIODIC,DM_BOUNDARY_PERIODIC,DM_BOUNDARY_GHOSTED,DMDA_STENCIL_BOX,nx,ny,nz,
                         PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,1,2,NULL,NULL,NULL,&da));
  PetscCall(DMSetFromOptions(da));
  PetscCall(DMSetUp(da));
  PetscCall(DMView(da,PETSC_VIEWER_STDOUT_WORLD));
  PetscCall(DMCreateMatrix(da,&A));

  PetscCall(MatDestroy(&A));
  PetscCall(DMDestroy(&da));
  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   test:
      nsize: 5

TEST*/