# [Getdp] Extraction of isocontours arrays

**"Gilles Quéméner"**
quemener at lpccaen.in2p3.fr

*Mon Sep 10 19:27:11 CEST 2012*

Hi All,
In fact I do not know exactly if this is a question for GetDP or for
Gmsh ... Therefore I am posting it to both mailing lists.
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.
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).
Any help is more than welcome.
Thanks a lot,
Gilles