[Gmsh] Characteristic lengths

[Martin Vymazal]

Hello to everyone,

 I'm looking for some info about available parameters that can be set for
a 'Box', 'Threshold' and 'MathEval'. A friend sent me an example geometry
file that uses a Box:

Field[1] = Box;
Field[1].VIn = 0.015;
Field[1].VOut = 8;
Field[1].XMin = -0.1;
Field[1].XMax = 0.1;
Field[1].YMin = -0.1;
Field[1].YMax = 0.1;

I'd like to try a Threshold and MathEval too, but found no info in Gmsh
manual. Could anybody point me to some other source of information
(example *geo files etc.)? Thank you.

             Martin Vymazal