[Gmsh] Interpolating mesh values

[Mayank Jog]

This is awesome!
2 Quick questions :
  1. When I use probe to get value @ a point, what interpolation kernel/
method is gmsh using?
        [I wanted to use an interpolation scheme such that if I specify a
point outside the mesh (which can happen when I spec a regular grid), I
don't want gmsh to extrapolate]

  2. I took a quick look @ the format of plugin(cutgrid) : {
http://www.manpagez.com/info/gmsh/gmsh-2.4.0/gmsh_53.php }
       Once I specify an origin, u & v vectors (for two axes), and number
of points "nu" and "nv" ;
          are "nu" and "nv" points sampled on both sides of the origin, or
along +u and +v?

Thank you!
Mayank

On Tue, Nov 28, 2017 at 7:39 AM, Christophe Geuzaine <cgeuzaine at uliege.be>
wrote:

>
>
> > On 27 Nov 2017, at 23:41, Mayank Jog <mayankjog at gmail.com> wrote:
> >
> > Hello,
> > I've started using gmsh recently, and I wonder if there is a
> functionality to interpolate data.
> >
> > I have a mesh, and a value associated with each element of the mesh
> (electric potential)*.
> > I want to use this mesh to calculate the value of the electric potential
> on a uniform cartesian grid specified by points (= (x, y, z) ; known in
> millimeters; = same unit as in $nodes)
>
> Plugin(Probe) for a single evaluation; or Plugin(CutGrid) and
> Plugin(CutBox) for multiple evaluations on regular grids.
>
> For example:
>
> Merge "data.msh";
> Plugin(Probe).X = 0.3;
> Plugin(Probe).Y = 0.3;
> Plugin(Probe).Z = 0.3;
> Plugin(Probe).Run;
>
>
> >
> > I'm guessing some sort of interpolation is needed...how would I go about
> it?
> >
> > I tried using MATLAB functions to interpolate, but they all use
> triangulation techniques which work for convex volumes. My volume is
> non-convex (it has a U-shape)...how would I do the interpolation? Does gmsh
> have a function to interpolate?
> >
> > Thank you,
> > Mayank
> >
> > *I have the  original mesh (containing $nodes, $elements, and
> $elementdata) in .msh format.
> > _______________________________________________
> > gmsh mailing list
> > gmsh at onelab.info
> > http://onelab.info/mailman/listinfo/gmsh
>
>
> --
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
>
> Free software: http://gmsh.info | http://getdp.info | http://onelab.info
>
>
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