Many thanks! I checked it, but noticed the Error : Colinear points in circum circle computation. Mistake is also clear in the mesh visualization. I use GMSH version 2.0.8. I don't know whether it might be a bug! Hom Nath -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.geuz.org/pipermail/gmsh/attachments/20080122/03fc03fb/attachment.html>