Re: Problems with defintion of a ContourFunction
- To: mathgroup at christensen.cybernetics.net
- Subject: [mg1582] Re: Problems with defintion of a ContourFunction
- From: rubin at msu.edu (Paul A. Rubin)
- Date: Sat, 1 Jul 1995 03:58:10 -0400
- Organization: Michigan State University
In article <3sg3od$8cq at news0.cybernetics.net>,
Martina Giarre <giarre at lgmhp3.epfl.ch> wrote:
->Hello,
->
->I have some problems in defining a ContourFunction. I cannot
->specify a color for a certain z-value in a ListContourPlot.
->
->I did some tests but the results are strange:
->
->
->test = Transpose[{{1,2,3,4,5,6},{1,2,3,4,5,6},
-> {1,2,3,4,5,6},{1,2,3,4,5,6},
-> {1,2,3,4,5,6},{1,2,3,4,5,6}}];
->
->g = {1,2,3,4,5,6};
->tc = Table[{Hue[d]},{d,0.4,1,0.1}];
->c[f_]:=While[f<=1,Hue[0.9]]
->ListContourPlot[test, PlotRange->{1,6},
-> Contours->g,
-> ContourStyle->tc,
-> ContourShading->True,
-> ContourLines->True,
-> ColorFunction->c];
->
->Unfortunately, this gives the chosen colors for the
->ContourLines but the ContourShading is not done in the
->right way. Instead of the intervall f<=1 being of the color
->Hue[0.9], all intervalls are of Hue[0.9].
->
->What is the mistake I do and how to solve the problem?
->
->Thank you in advance.
->
->Martina Giarre
->
The argument ListContourPlot sends to c is not the contour value but the
*scaled* contour value (domain 0 to 1). Change f<=1 to f <= .2; this is
not exactly what you were proposing, but then values of the function less
than 1 will not plot if your smallest selected contour is 1.
You do not want While, by the way - it causes a loop. Try
If[f<=.2,Hue[0.9],...]
where ... is replaced by the color you like for the other segments.
Paul
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