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

*To*: mathgroup at smc.vnet.net*Subject*: [mg50493] Re: ColorFunctions again (making z=0 be different from z=1)*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Wed, 8 Sep 2004 05:05:43 -0400 (EDT)*Organization*: Universitaet Leipzig*References*: <chk0cu$sj$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de*Sender*: owner-wri-mathgroup at wolfram.com

Hi, a) Hue[] is periodic with its argument with period one and Hue[0] is the same as Hue[1] but if you set the color function to ColorFunction->(Hue[0.8*#] &) you have romoved the effect b) the typical colors from Maps are lscape=Compile[{{v,_Real}},{0.25660999433616455 + v*(-0.15450689601371334 + v*(16.99064278686296 + v*(-49.77485354775084 + (53.311185629847536 - 20.331201294602224*v)*v))), 0.5950036100590319 + v*(0.9030709139591158 + v*(-4.7684534226105955 + v*(39.51236857804843 + v*(-117.41187124896338 + (131.37166677177956 - 50.03797646732823*v)*v)))), 0.20815128511236033 + v*(0.911878579970309 + v*(-4.479304425265597 + v*(36.027512397958255 + v*(-101.52716099689235 + (110.30681084859079 - 41.31008420034276*v)*v))))}] LandscapeColor[v_]:=RGBColor @@ lscape[v] c) Look for the Graphics`Legend` standard package and it you don't like it the book by Tom Wickham-Jones about Mathematica Graphics has a nicer legend for density and contour plots. The ExtendGraphics package is on MathSource Regards Jens 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?]