Scipy.spatial.Delaunay fail to produce the tetrahedron for all particles
Dear developer, I am using Scipy.spatial.Delaunay to do some analysis. I found that the Delaunay model can not produce the tetrahedron for my simulated 3D particles which is at the center of a halo. Lots of it are not included in the tri.vertices. For example, I select about ~2300 particles in the center, and do the triangulation. But the tri.vertices only have a shape of (484, 4)! I think this should be a problem of the Hull's accuracy setting. Can I know where I can tune this? Or any suggestions are welcome. I have report this in here, http://projects.scipy.org/scipy/ticket/1728. You can find the 3D particles' position in the attached .txt file Thanks. ilaudy
Dear Ilaudy, 25.09.2012 11:57, Ilaudy kirjoitti:
I am using Scipy.spatial.Delaunay to do some analysis. I found that the Delaunay model can not produce the tetrahedron for my simulated 3D particles which is at the center of a halo. Lots of it are not included in the tri.vertices. For example, I select about ~2300 particles in the center, and do the triangulation. But the tri.vertices only have a shape of (484, 4)! I think this should be a problem of the Hull's accuracy setting. Can I know where I can tune this? Or any suggestions are welcome.
Yes, this is an issue due to QHull not including some vertices in the triangulation due to precision issues. This can probably be avoided by supplying additional options to Qhull. For instance, "QJ" should force it to produce a triangulation including all points. Unfortunately, currently there's no way to pass custom options to scipy.spatial.Delaunay, but adding that is in the plans. -- Pauli Virtanen
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Ilaudy -
Pauli Virtanen