[Gmsh] Extraction of isocontours arrays

[Christophe Geuzaine]

On 07 Sep 2012, at 16:38, Quéméner Gilles <quemener at lpccaen.in2p3.fr> wrote:

> Hi All,
> 
> In fact I do not know exactly if this is a question for GetDP or for Gmsh ...
> 
> Assume that using GetDP, I have solved Laplace equation in a 2D domain with or without holes and that I plot isocontours of the scalar potential using Gmsh.
> I would like to be able to retrieve arrays containing the (x, y)- coordinates of the points making these isocontours, but I don't know how to get these arrays variables or export the coordinates in ascii files. In 2D, Gmsh is able to plot a given number of iso-value contours of a scalar field, thus there should be a way to get these coordinates.
> 

Plugin(Isosurface), then save the View e.g. as "Generic text". You'll have to sort the points, though...

> A similar but more complicated problem arises in 3D. In this case, I would like to obtain arrays of (x, y, z)-coordinates along the lines corresponding to the intersection of isopotential surfaces with the different domains surfaces (planar or curved and with or without holes).
> 

You could also use Plugin(Isosurface) and then cut it with e.g. Plugin(CutPlane). But this is OK only for plane cuts; nothing is there to cut by geometry surfaces...

Christophe



> Any help is more than welcome.
> Thanks a lot,
> 
>  Gilles
> 
> -- 
> 
>   Gilles Quéméner
> 
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-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine