Re: Question about interpolation and ListPlot3D
- To: mathgroup at christensen.cybernetics.net
- Subject: [mg1493] Re: [mg1460] Question about interpolation and ListPlot3D
- From: twj (Tom Wickham-Jones)
- Date: Mon, 19 Jun 1995 01:26:10 -0400
Zvi Wiener writes
> I have an array representing 3 dimensional points
>in a form of their Eucledean coordinates:
>arr = {{x1,y1,z1}, ... ,{xN,yN,zN}};
>(they were generated from a very smooth function).
>
>1. I wish to generate a 3D plot of this surface (approximately),
>but format of ListPlot3D does not permit it, since my points
>{xi, yi} do not form a regular grid.
>How I can draw the surface?
I have written a package SurfaceGraphics3D.m that will take data
in the form {{x1,y1,z1}, ... ,{xN,yN,zN}} and plot a surface over
it.
>2. I would like to find value of this function at another point
>{x, y}, the answer obviously depend on the way the function was
>interpolated (extrapolated), but I am interested in any way, as
>simple as possible.
>How to extract the Interpolating Function's value at {x, y} ?
I have a related package TriangularInterpolate.m that will do this.
Both of these packages are based on some MathLink delaunay triangulation
code. All the code is available in a set of packages I wrote called
ExtendGraphics which is available from MathSource item number 0207-324.
Tom Wickham-Jones
WRI