[Gmsh] List of Questions

[Joe Koski]

I've been trying to create meshes with some success, but some questions have
regarding the proper use of GMSH have arisen. I'm using GMSH 1.52.1 on a
Macintosh with OS X 10.3.4.

Here are the questions, in no particular order:

1) My .msh files follow the Version 1 format, not Version 2. For example,
the node section starts with $NOD, not $Nodes. Is this correct? When will
Version 2 be used?

2) For Diriclet type boundary conditions, is it possible to associate a
unique value or a flag with a geometric line or surface (other than line or
surface number) that can be used later to trigger a translator to recognize
that particular boundary? For example, if the temperature at a boundary is
to be 293 K, is it possible to enter the value 293 somewhere during the
geometry construction? Should I use physical entities for this or is there
another mechanism?

3) If I zoom and pan to a particular view on the screen, is it possible to
interactively write a .jpg of that view? I know how to do a screen capture,
but resolution can be lost that way.

4) So far I have been unsuccessful in recombining a simple 1 x 1 square mesh
of triangles to obtain some quadrilaterals. First, when I try to create a
Plane Surface, I am told to "Select Exterior Boundary" and I successfully
pick a line loop. Then I am asked to "Select Hole Boundary," but there is no
hole. What to do? I've tried selecting the exterior boundary again, without
success. When I do fiddle somehow and successfully get a mesh, I do
"Define," "Recombine," and "Select Surface" then 'e' for end, and nothing
happens to the mesh. Any suggestions? My .geo file keeps changing, or I
would include it.

5) I have Gmsh.app in my /Applications folder. Is there a way of running
gmsh from the terminal command line on a Mac? Otherwise, how do you access
the command line options?

I realize that GMSH is primarily an academic teaching tool, but it will
probably suffice for the type of simple finite element thermal models that I
usually build. Any help in resolving these issues will be greatly
appreciated.

Joe Koski