On Wed, Mar 16, 2016 at 7:23 AM, gouarin <[email protected]
<mailto:[email protected]>> wrote:
Hi,
I try to use PETSc to solve BEM problem so I need to construct a
surface with 3D coordinates. First of all, I would like to plot the
mesh and I think that the output of the viewer is completely wrong.
Here is a Python example
import sys, petsc4py
petsc4py.init(sys.argv)
import numpy as np
import petsc4py.PETSc as petsc
coords = np.array([[0, 0, 0],
[1, 0, 0],
[0, 1, 0],
[1, 1, 0],
[0, 0, 1],
[1, 0, 1],
[0, 1, 1],
[1, 1, 1],
], dtype=np.double)
cells = np.array([[0, 1, 3, 2],
[1, 5, 7, 3],
[0, 4, 6, 2],
[2, 3, 6, 7],
This quad is mis-specified, since 3-6 is a diagonal.
[0, 1, 5, 4],
[4, 5, 7, 6],
], dtype=np.int32)
dm = petsc.DMPlex().createFromCellList(2, cells, coords,
interpolate=False, comm=petsc.COMM_WORLD)
viewer = petsc.Viewer().createHDF5('cube.h5', 'w')
dm.view(viewer)
If you look at the cells in the cube.h5, the numbering of the points
is wrong.
I rewrote this in C, and I can visualize the surface. I then run it using
./ex18 -dm_view hdf5:dm.h5
and process that file
./bin/petsc_gen_xdmf.py dm.h5
This won't quite work when you have interpolate = PETSC_FALSE, because
then I do not force the 'viz' output,
however it can be forced with a viewer format.
Thanks,
Matt
Thanks,
Loic
--
Loic Gouarin
Laboratoire de Mathématiques
Université Paris-Sud
Bâtiment 425
91405 Orsay Cedex
France
Tel: (+33) 1 69 15 60 14 <tel:%28%2B33%29%201%2069%2015%2060%2014>
Fax: (+33) 1 69 15 67 18 <tel:%28%2B33%29%201%2069%2015%2067%2018>
--
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which
their experiments lead.
-- Norbert Wiener
