[Gmsh] Two questions:physical entities and Transfinite&Elliptic algorithm

[=?gb2312?q?=CA=E9=20=C0=EE?=]

Dear gmsh,
I am a gmsh user in China.I just try to learn FEM by it.Now I just meet two problems in using gmsh.
One is about physical entities.The pdf document says,"The purpose of physical entities is to assemble elementary entities into larger, possibly overlapping groups, and to control the orientation of the elements in these groups.If physical entities are defined, the output mesh only contains those elements that belong to physical entities. "This is useful,but I can't make it.The orientation(the sequence of the node's num ) is the same before and after I define some phisical entities.So is the output mesh which contains all the meshing elements I defined-physical or not.Would you please show me how to  use physical entities effectively,maybe give me an example?
The other is about Transfinite&Elliptic algorithm.Would you please give me a brief introduction about these two algorithm?
I would appreciate if you reply.
                         a GNU supporter, Soil






---------------------------------
Do You Yahoo!?
150ÍòÇúMP3·è¿ñËÑ£¬´øÄú´³ÈëÒôÀÖµîÌÃ
ÃÀÅ®Ã÷ÐÇÓ¦Óо¡ÓУ¬ËѱéÃÀͼ¡¢ÑÞͼºÍ¿áͼ
1G¾ÍÊÇ1000Õ×£¬ÑÅ»¢µçÓÊ×ÔÖúÀ©ÈÝ£¡
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.geuz.org/pipermail/gmsh/attachments/20050409/d06370e2/attachment.htm