Re: Re: A Dead Thread? Re. Coloring ExtendGraphics ListContourPlot s...

*To*: mathgroup at smc.vnet.net*Subject*: [mg22201] Re: [mg22162] Re: [mg19437] A Dead Thread? Re. Coloring ExtendGraphics ListContourPlot s...*From*: Hartmut Wolf <hwolf at debis.com>*Date*: Fri, 18 Feb 2000 02:34:37 -0500 (EST)*Organization*: debis Systemhaus*References*: <200002170623.BAA04319@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Mark Harder schrieb: > > I am trying to create contour plots for irregular data, and after some > work, I downloaded the right ExtendGraphics package, derived from Tom Wickham-Jones' > book. I was able to get contour plots without color, but using the ColorFunction > option did not work. Experimenting with equally spaced data showed that I > could get colored ListContourPlot-s with the v.3.0.1 built > -in function, but that the ExtendGraphics version seems to ignore my ColorFunction > option setting. In searching the Archives of this group in MathSource, I came > upon Laurence Lours' posting (see above) in which he describes > the same problem (last Aug.), but there doesn't seem to be any response to > his last posting. > Has anyone found a solution to this problem, or some sort of work-around? > Unlike Laurence, I am using a Windows NT4.0 system, with Mathematica v3.0.1. > Thanks, > mark e. harder > harderm at ucs.orst.edu Hello Mark, ...I haven't tried this out, but having a look into TWJ's book pp. 480 it could work if you procceed as (1) load Needs["ExtendGraphics`TriangularInterpolate`"] (2) generate the trangular interpolation function from your data fun = TriangularInterpolate[data] (3) generate a regular array of new data new = Table[fun[x,y], {x,...},{y,...}] (4) use _standard_ built-in ListContourPlot Step (1)-(3) are nothing else but a interpolation problem. Mathematica ListInterpolation doesn't work in that case, since it needs a not neccessarily equally spaced but rectangular grid. If you can get a different interpolation algorithm, or write your own from first principles, you could also use that instead. Kind regards, Hartmut

**References**:**Re: A Dead Thread? Re. Coloring ExtendGraphics ListContourPlot s...***From:*"Mark Harder" <harderm@ucs.orst.edu>