[petsc-dev] DMGetDS in fortran

[Adrian Croucher]

hi

I'm just getting back to using DMPlex after a few months busy on other 
stuff, and looking at the TS ex11 problem, a few things have changed in 
the meantime.

TS ex11 used to set up a PetscSection manually to define the data 
layout, for constructing vectors on it. Now it seems this is handled by 
creating a PetscFV object and adding it to the PetscDS in the DMPlex.

I set up a simplified code to test this in isolation, and it works in C 
but not in Fortran (code below). It gets this error- looks like maybe 
something wrong with the fortran interface:

[0]PETSC ERROR: --------------------- Error Message 
--------------------------------------------------------------
[0]PETSC ERROR: Null argument, when expecting valid pointer
[0]PETSC ERROR: Null Pointer: Parameter # 2
[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html 
for trouble shooting.
[0]PETSC ERROR: Petsc Development GIT revision: v3.5.2-1240-gd4bc1ae  
GIT Date: 2014-11-25 11:37:47 -0600
[0]PETSC ERROR: ./testplexf on a linux-gnu-c-opt named des108 by acro018 
Fri Nov 28 16:02:22 2014
[0]PETSC ERROR: Configure options --download-netcdf --download-exodusii 
--with-hdf5-dir=/usr/lib 
--with-numpy-dir=/usr/lib/pymodules/python2.7/numpy --
with-scientificpython-dir=/usr/lib/python2.7/dist-packages/scipy 
--with-petsc4py-dir=/usr/local/lib/python2.7/dist-packages/petsc4py 
--download-triangl
e --with-fortran-interfaces=1 --download-ptscotch --download-chaco 
--download-ctetgen
[0]PETSC ERROR: #1 DMGetDS() line 3407 in 
/home/acro018/software/PETSc/code/src/dm/interface/dm.c

Also, any chance of a fortran interface to DMPlexCreateFromFile()? It 
appears to be missing at the moment.

Regards, Adrian
--

program testplex

   implicit none

#include <finclude/petscsys.h>
#include <finclude/petscvec.h>
#include <finclude/petscdm.h>

   PetscInt, parameter :: dim = 3, dof = 1
   MPI_Comm :: comm
   DM :: dm, dist_dm, ghost_dm
   PetscErrorCode :: ierr
   character(40) :: filename = "column.exo"
   PetscInt :: localsize
   PetscFV :: fvm
   PetscDS :: ds
   Vec :: X

   call PetscInitialize(PETSC_NULL_CHARACTER, ierr); CHKERRQ(ierr)
   comm = PETSC_COMM_WORLD

   call DMPlexCreateExodusFromFile(comm, filename, PETSC_TRUE, dm, 
ierr); CHKERRQ(ierr)

   call DMPlexSetAdjacencyUseCone(dm, PETSC_TRUE, ierr); CHKERRQ(ierr)
   call DMPlexSetAdjacencyUseClosure(dm, PETSC_FALSE, ierr); CHKERRQ(ierr)

   call DMPlexDistribute(dm, 0, PETSC_NULL_OBJECT, dist_dm, ierr)
   CHKERRQ(ierr)
   if (dist_dm /= 0) then
      call DMDestroy(dm, ierr); CHKERRQ(ierr)
      dm = dist_dm
   end if

   call DMPlexConstructGhostCells(dm, PETSC_NULL_CHARACTER, 
PETSC_NULL_INTEGER, &
        ghost_dm, ierr); CHKERRQ(ierr)
   if (ghost_dm /= 0) then
      call DMDestroy(dm, ierr); CHKERRQ(ierr);
      dm = ghost_dm
   end if

   call DMView(dm, PETSC_VIEWER_STDOUT_WORLD, ierr); CHKERRQ(ierr)

   call PetscFVCreate(comm, fvm, ierr); CHKERRQ(ierr)
   call PetscFVSetNumComponents(fvm, dof, ierr); CHKERRQ(ierr)
   call PetscFVSetSpatialDimension(fvm, dim, ierr); CHKERRQ(ierr)
   call DMGetDS(dm, ds, ierr); CHKERRQ(ierr)
   call PetscDSAddDiscretization(ds, fvm, ierr); CHKERRQ(ierr)

   call DMCreateGlobalVector(dm, X, ierr); CHKERRQ(ierr)
   call VecGetLocalSize(X, localsize, ierr); CHKERRQ(ierr);
   print *, "Local size:", localsize

   call DMDestroy(dm, ierr); CHKERRQ(ierr)
   call PetscFinalize(ierr); CHKERRQ(ierr)

end program testplex

-- 
Dr Adrian Croucher
Senior Research Fellow
Department of Engineering Science
University of Auckland, New Zealand
email: a.croucher at auckland.ac.nz
tel: +64 (0)9 923 84611