[Gmsh] The tags in gmsh.

[Geordie McBain]

2011/6/14 Jayesh Badwaik <jayesh.badwaik90 at gmail.com>:
> Hi,
>
> I have read that the file format for describing the elements in gmsh is as
>
> follows
>
> elm-number elm-type number-of-tags < tag > ... node-number-list
>
> My question is how to insert the tags for elements. Is there anyway to
> manually insert tags?

I'm not sure what you mean by `manually insert' but the usual way to
generate tags is suggested in the description for `number-of-tags'

http://geuz.org/gmsh/doc/texinfo/gmsh.html#MSH-ASCII-file-format

  number-of-tags
      gives the number of integer tags that follow for the n-th
element. By default, the first tag
      is the number of the physical entity to which the element
belongs; the second is the
      number of the elementary geometrical entity to which the element
belongs; the third is the
      number of mesh partitions to which the element belongs, followed
by the partition ids
      (negative partition ids indicate ghost cells). A zero tag is
equivalent to no tag.

i.e. define physical entities corresponding to your tag-sets.  Most
commonly in finite element work, we have Physical Volumes for domains
or subdomains (e.g. where different PDEs are to be solved, or between
which the coefficients jump) and Physical Surfaces for boundary
patches.

Does that help?