[GRASS-user] Application of r.color

[Glynn Clements]

Micha Silver wrote:

> > I have a script where I create a map (using mapcalc) and I want to 
> > attribute a color (gray for instance) but it ranges from 0 to 5 so I 
> > cannot attribute gray0-1 neither gray0-255. What can I do to attribute 
> > a color table that stretches its color attibution to the image max and 
> > minimum values?
> >
> How about creating a color rules file with percentages (instead of 
> values), then, regardless of the actual raster values, the colors will 
> be "automatically" spread between the min and max color. i.e.
> 0% 0 0 0
> 100% 255 255 255
> This will create a spread of colors from black to white.

That's exactly what color=grey does:

	$ cat $GISBASE/etc/colors/grey
	0% black
	100% white

More generally, these use only relative (percentage) values:

	aspect bcyr bgyr byg byr elevation grey gyr haxby rainbow ramp
	ryb ryg sepia wave

-- 
Glynn Clements <glynn at gclements.plus.com>