[Gmsh] defingin and saving sets

[Roland Tollenaar]

Hi All,

I am new to gmsh. Most of its basic functionality in the interactive 
mode I think I understand.

But I am having severe problems defining sets of nodes and elements 
along with the the set of all nodes/elements which I believe should be 
possible.

It appears that by selecting a physical entity (group) and saving as unv 
  whereby care is take to save both all _and_ groups, the defined sets 
should be saved along with the entire mesh.

This is what I am doing

Load geometry (step) -> Physical entities->Add->Surface-> select and 
press e->mesh->3D->save as->File.unv -> check both options->Press OK

But I cannot see that the sets are stored in the unv file.

Secondly, there seems to be no possibility of giving the set a name such 
that it can be identified in the file.

I need these sets to define contraints, and apply loads to. Also to 
define contact surfaces for the solver etc.

I would be much obliged if someone could tell me what I am doing wrong. 
This is quite frustrating.

If there is a manner to do it with scripting, I would also be very 
interested to know. So far I have not seen how to in the manual. But the 
manual is rather large so I am still looking.

Using Gmsh version 2.1.1(linux) and 2.2.5(Windows)

Kind regards,

Roland