[Gmsh] Using Gmsh as a post-processor

[Geordie McBain]

2010/10/19 Rami Ben-Zvi <rami.ben-zvi at weizmann.ac.il>:
> Is it possible in Gmsh to display results along line of nodes and elements
> as x-y graphs (e.g., the solid and fluid nodes and elements temperature
> fields along an axial line)? At present I do it manually, by importing parts
> of the output into Excel, which is rather cumbersome. The answer to this
> question is therefore the most urgent.

Does the answer at http://www.geuz.org/pipermail/gmsh/2010/005676.html help?

> The geometry of the steam generator we develop is rather inconvenient to
> display, since it comprises of several concentric cylinders having narrow
> gaps between each other, and also having bases. In order to display the
> results, it would be convenient if parts of the model can be unselected, so
> that only desirable parts temperatures contours, say, are displayed. The way
> I do it now is by defining many views (around 100), each devoted to a
> certain group of the nodes or element and a certain field values. Is there a
> more elegant and simpler way to do it? Are the "Physical Names" properties
> useful for this? There is very limited documentation of their use in the
> post-processing part of Gmsh (provided I do not use Gmsh geometry and mesh
> processors).

I think one way would be to set the "elementary entity" or "physical
entity" tag of the elements in question.  You can select visibility by
either of these.  These are two of the three or four integer tags that
each element gets in the $Elements block.  Would it be possible to
modify your output routine to do that?  I don't think you need to
worry about Physical Names, although it is nicer to refer to "wall"
than physical entity 2, e.g.