Hi!
I want to plot three raster images side by side. They cover the same
area, and are just to point out any obvious differences. In order to do
that, the colourtables used needs to be identical. In GRASS, these are
automatically calculated from the span of the data, and in my case,
this is slightly different. I would like to set the limits of the
colourtable to be the same.
Is there an easy way to do this in GRASS, or do I have to modify the
rastersthemselves with r.mapcalc (groan :D)?
Jose, I am not sure if this is what you want, but you can set the colors with r.colors
If you have three rasters with ranges from 0-100, 25-125, 50-150, then run something like
r.colors color=rules map=map1
0 white
100 black
end
r.colors color=rules map=map2
25 white
125 black
end
etc.
This might do what you are looking for. I am not sure if this is what you want though. For my data, this might be deceiving to the viewer, but mebbe that is what you want
-Ian
On Feb 16, 2005, at 7:14 AM, Jose Luis Gomez-Dans wrote:
Hi!
I want to plot three raster images side by side. They cover the same
area, and are just to point out any obvious differences. In order to do
that, the colourtables used needs to be identical. In GRASS, these are
automatically calculated from the span of the data, and in my case,
this is slightly different. I would like to set the limits of the
colourtable to be the same.
Is there an easy way to do this in GRASS, or do I have to modify the
rastersthemselves with r.mapcalc (groan :D)?
On Wednesday 16 Feb 2005 16:38, Ian MacMillan wrote:
Jose, I am not sure if this is what you want, but you can set the
colors with r.colors
I realised that you can copy the colour table from one raster map to
another using r.colors' rast option. This is exactly what was needed:
the same colours for each raster, just pick one as a baseline, and then
apply that table to all others. However, it would be nice to be able to
have huge control over colourtables (and a nice collection of
colourtables) like in GMT.
Cheers,
Jose
--
Jose L Gomez-Dans, Research Assistant
Bristol Glaciology Centre, Geographical Sciences/CPOM
University of Bristol, Bristol, UK
> Jose, I am not sure if this is what you want, but you can set the
> colors with r.colors
I realised that you can copy the colour table from one raster map to
another using r.colors' rast option. This is exactly what was needed:
the same colours for each raster, just pick one as a baseline, and
then apply that table to all others. However, it would be nice to be
able to have huge control over colourtables (and a nice collection of
colourtables) like in GMT.
'r.colors rules=' should give you total control. Use it to set the color
table for the entire range (ie beyond the range of any one map);
copy it to all maps with the 'r.colors rast=' command; and use
'd.legend range=' to extend the legend to the full extent of your color
table (otherwise it snaps to the max/min values of that particular map).
