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Re: ColorFunctions again (making z=0 be different from z=1)

• To: mathgroup at smc.vnet.net
• Subject: [mg50512] Re: [mg50488] ColorFunctions again (making z=0 be different from z=1)
• From: Bob Walker <walkerbg at ieee.org>
• Date: Wed, 8 Sep 2004 05:15:36 -0400 (EDT)
• References: <200409070943.FAA00803@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

For the first question, one possibility is the ColorFunction defined as:
 ColorFunction\[Rule](Hue[.62+.91#]&),
The .62 starts at blue (since I like to start with blue) and the .91 
stops before it returns to full blue.  You still get all the colors in 
between since Hue does a Mod 1 on its arg.

Or closer to the default:
ColorFunction\[Rule](Hue[91#]&),
which will start at red and not get all the way back to red.

For contour legends, I suggest you try the following
LabelContour.m, which is available on MathSource, is writen by Tom 
Wickham-Jones and is discussed in his excellent book: Mathematica 
Graphics.  Note that the book is written for Mathematica 3 so there are some 
differences.  The package on MathSource has been updated for Mathematica 4 (and 5).

Good luck
Bob Walker

AES/newspost wrote:

>The simple  ColorFunction->Hue  option in Plot3D, ContourPlot, and 
>DensityPlot, makes z = 0 appear the same as z = 1 (i.e., both bright 
>red), a situation which seems to me to make these plots confusing 
>and more difficult to interpret, given that "high peaks" and "sea
>level valleys" may be the most interesting features of such a plot.
>
>Do others have any favorite, not too messy ColorFunctions that
>make values near z = 0 tend toward white, or grey, or less bright,
>or something so that there's a clearly unidirectional visual
>effect going from values of z near 0 to those near z = 1?
>
>[And as a side question, a simple Prolog or Epilog code to put 
>one of those scaled and labelled vertical color bars alongside a
>ContourPlot or DensityPlot, perhaps with the same vertical
>height as the plot itself?]
>
>
>  
>

• References:
  • ColorFunctions again (making z=0 be different from z=1)
    • From: AES/newspost <siegman@stanford.edu>