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

  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[])
{
  PetscErrorCode ierr;
  PetscInt       nx = 2;
  PetscInt       ny = 2;
  PetscInt       nz = 128;
  DM             da;
  Mat            A;

  ierr = PetscInitialize(&argc,&argv,NULL,NULL);if (ierr) return ierr;

  ierr = 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);CHKERRQ(ierr);

  ierr = DMSetFromOptions(da);CHKERRQ(ierr);
  ierr = DMSetUp(da);CHKERRQ(ierr);
  ierr = DMView(da,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = DMCreateMatrix(da,&A);CHKERRQ(ierr);

  ierr = MatDestroy(&A);CHKERRQ(ierr);
  ierr = DMDestroy(&da);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return ierr;
}

/*TEST

   test:
      nsize: 5

TEST*/