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>
• 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?]

```

• Prev by Date: Re: ColorFunctions again (making z=0 be different from z=1)
• Next by Date: Re: ColorFunctions again (making z=0 be different from z=1)
• Previous by thread: Re: ColorFunctions again (making z=0 be different from z=1)
• Next by thread: Re: ColorFunctions again (making z=0 be different from z=1)