Hi,

On 18.4.2017 18:27, rmk236@gmail.com wrote:

I am trying to build a custom rectangle mesh, but it seems that I am failing to do a proper one. I wrote a small python script to build the rectangle, using Delaunay triangulation [1]. This results in a file [2] that looks OK when compared with '/meshes/2d/rectangle_tri.mesh'. However, when I try to use this file into the a slightly modified version of '/examples/linear_elasticity/linear_elastic_interactive.py' [3], it raises an orientation error [4].

I really don't undestand what seems to be the issue here. Is it an ordering in the triangular elements? Does Sfepy presupose a specific ordering?

The medit format you generate assumes 1-based indexing - use

     for t in sim + 1:
         f.write('%d\t%d\t%d\t3\n' % (t[0], t[1], t[2]))

in WriteMesh() in [1]. Then your script works correctly.

r.

[1] http://www.codesend.com/view/b6612f600b38f6f8552dc89ce072c938/ [2] http://www.codesend.com/view/25adf8bbe8e29f151d068b7ba08b4c82/ [3] http://www.codesend.com/view/910a5af4ba2a2b46f8a83572a7280529/ [4] Error below:

...

sfepy: reading mesh [line2, tri3, quad4, tetra4, hexa8] (MyMesh.mesh)... sfepy: ...done in 0.00 s sfepy: warning: bad element orientation, trying to correct... sfepy: warning: bad element orientation, trying to correct... Traceback (most recent call last): File "./linear_mod.py", line 98, in <module> main() File "./linear_mod.py", line 44, in main domain = FEDomain('domain', mesh) File "/home/homeGlobal/lcampos/.local/lib/python2.7/site-packages/sfepy-2017.1-py2.7-linux-x86_64.egg/sfepy/discrete/fem/domain.py", line 61, in __init__ self.fix_element_orientation() File "/home/homeGlobal/lcampos/.local/lib/python2.7/site-packages/sfepy-2017.1-py2.7-linux-x86_64.egg/sfepy/discrete/fem/domain.py", line 146, in fix_element_orientation raise RuntimeError('elements cannot be oriented! (%s)' % key) RuntimeError: elements cannot be oriented! (2_3)

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