[GRASSLIST:9907] Re: ps.map multiple rasters??

[Hamish]

>>>> I wonder if there is a way of inserting more than one raster into a
>>>> map made with ps.map. This is possible with vectors, is it possible
>>>> with rasters?? how??
> ..
>>> For each ps.map run, only one raster map layer (or set of layers or
>>> imagery group; see below) can be requested. ...
>>> 
>>> r.patch could help
..
>> also you could make a ps.map Encapsulated PostScript output map, then
>> place the EPS file(s) within another ps.map container map. Possibly 
>> even a (mostly) blank one if say you want 4 maps arranged as so:
..
> thanks for your replay, I will try. In fact r.patch works fine if the
> maps are of the same type, otherwise the reconstruction of the color
> map can make bad results..

the eps within another ps.map is useful if the regions will be different
(e.g. overview map + detail map at different places on the page).

If you are interested in just overlaying maps in both the same region &
place on the page, it is best to just use r.patch for maps of the same
color maps, or as Glynn explained to me on the mailing lists a few
months ago, use r.mapcalc to create red,green,blue maps using the "#"
operator combined with if() statements to provide the order (see the
r.mapcalc help page). My less efficient method was to export a PNG dump
of the display monitor, then reload that image into GRASS as a new
raster.



Hamish