[GRASSLIST:2262] Re: r.patch -- problem solved
rshepard at appl-ecosys.com
Fri Aug 3 15:39:07 EDT 2001
On Fri, 3 Aug 2001, Malcolm Williamson wrote:
> Check out the man page for r.colors; it describes how color ramps are defined.
> If you actually look at your color table (under $LOCATION/colr), you'll see how
> it works. Most of the colortables (excluding "rules" and "random", I think)
> defined in r.colors are written as ramps, meaning that there are not specific
> colors written in the colr file. Try zooming in to part of your DEM, so that you
> can see individual cells, and compare nlev=32 to nlev=256. I believe you'll see
> a difference, using d.what.rast to identify cell values associated with
> different colors. I just tested this, so I know it to be true.
I'll have to read r.colors again until I fully understand this. Looking at
one of the files in colr/, I see this:
[rshepard at salmo colr]$ less temp_dem
% 1200 2721.300048828125
It looks to me that there are 12 colors and each is assigned to a range of
values, the lower bound of which is specified? The range of elevation values
here (I believe in meters) is on the first line. FWIW, I had nlev=256 set
for this display.
I'll have to keep digging and working to understand colors in GRASS.
Dr. Richard B. Shepard, President
Applied Ecosystem Services, Inc. (TM)
2404 SW 22nd Street | Troutdale, OR 97060-1247 | U.S.A.
+ 1 503-667-4517 (voice) | + 1 503-667-8863 (fax) | rshepard at appl-ecosys.com
Making environmentally-responsible mining happen.
More information about the grass-user