1. Do not install gmsh or getdb with debian.  Instead, simply download the ONELAB software bundle

   http://www.onelab.info/wiki/ONELAB


2. unzip it

   cd Downloads/onelab-Linux64

   (run the local gmsh)

   ./gmsh

     File-->Open (Browse) models/magnetometer/magnetometer.pro

     Run

* ******************************************************************

There are a lot of FEM Mesh programs and info

gmsh   - seems like one of the most basic and powerful mesh generators
netgen - seems like another of the most basic and powerful mesh generators,
         but doesn't seem supported well, so can't just download it easily,
         and no longer seems to be compiled into freecad

You can generate a mesh directly in python code in freecad

https://www.freecadweb.org/wiki/FEM_Mesh



gmsh has a gui, but I don't believe it's a great 3-D graphical tool

At some point I could see :

  freecad - use for drawing and displaying 
  gmsh    - use for meshing
  ccx     - use for solving

  It seems like freecad and ccx come working good right out of the box

  We somehow need to learn how to mesh off line with gmsh