Hi Raphael, I do recommend upgrading and going the way Anna mentioned, especially if you are dealing with a large number of maps. But if that is not an option here are the steps I'd take:
1) run r.info -r on each map to get the min/max range 2) user r.colors with one of the maps and the rule option to set you color table to that map. Your rules might look something like this min_value red (max - min)/2 yellow max_value blue end -- by substituting the min / max in the above you get a colortable going from red to blue with yellow in the middle 3) copy the color table you just set to the other maps using r.color rast option. Take a look at r.color man page for more info http://grass.osgeo.org/grass64/manuals/r.colors.html Daniel On Tue, Jul 22, 2014 at 11:46 PM, <[email protected]> wrote: > Thank you Daniel and Anna for the suggestions. > Daniel, I wonder how I might display the ‘common’ colour legend when > visualising the maps? > When the maps are visualised, the colour legend changes to the min max of > the current map displayed. > > Anna, I use GRASS 6.4.2 – so I guess I should upgrade… > > Thank you again. > Raphael. > > > __________________________ > > Raphael *VISCARRA ROSSEL* | Principal Research Scientist | CSIRO Land and > Water | Bruce E. Butler Laboratory, Clunies Ross St, Black Mountain, Acton > ACT 2601 | PO BOX 1666 Canberra ACT 2600 | t. +61 2 6246 5945 | m. +61 > 467 769 364 | Chair International Union of Soil Science Working Group on > Proximal Soil Sensing | www.researcherid.com/rid/B-4061-2011 | > scholar.google.com.au/citations?hl=en&user=KpJdvKEAAAAJ > > > > > From: Anna Petrášová <[email protected]> > Date: Wednesday, 23 July 2014 12:15 pm > To: Daniel Victoria <[email protected]> > Cc: "Viscarra Rossel, Raphael (L&W, Black Mountain)" < > [email protected]>, grass <[email protected]> > Subject: Re: [GRASS-user] create a common colour scale > > Hi, > > in case you use GRASS 7, r.colors accepts multiple maps or a file with > the map names. So this should do it: > r.colors map=precip1,precip2,precip3 color=precipitation > > Also, have a look at temporal modules (GRASS 7 only). You can register > the series of maps as a dataset (t.create, t.register) and then you can > easily get the min, max values for the entire series and there is also > t.rast.colors. > > Anna > > > On Tue, Jul 22, 2014 at 9:41 PM, Daniel Victoria < > [email protected]> wrote: > >> Hi Raphael, >> >> This is what I did some time ago when I had the same problem >> 1) Find out the overall minimun and maximum precipitation over all maps. >> 2) Use r.colors with the rules option to compose a colortable that cover >> my entire precip range. >> 3) Apply the same colortable to all maps >> 4) plot and be happy >> >> Hope it helps >> Daniel >> >> >> On Tue, Jul 22, 2014 at 10:01 PM, <[email protected]> >> wrote: >> >>> Hello >>> I wonder if anyone knows how to create a common colour scale for >>> different raster maps? >>> I want to display all six maps on the same page with the single colour >>> scale but I cannot find how to do this in GRASS. >>> >>> More specifically, I have six raster maps of rainfall for different >>> time periods (each has a different range of values) and I would like to >>> display them all with the same colour scale. The colour scale needs to be >>> constructed using the min and max values of the set of six maps (and not >>> just individual maps. >>> >>> Will appreciate any input please. Thank you, >>> >>> Raphael. >>> >>> __________________________ >>> >>> Raphael *VISCARRA ROSSEL* | Principal Research Scientist | CSIRO Land >>> and Water | Bruce E. Butler Laboratory, Clunies Ross St, Black Mountain, >>> Acton ACT 2601 | PO BOX 1666 Canberra ACT 2600 | t. +61 2 6246 5945 | >>> m. +61 467 769 364 | Chair International Union of Soil Science Working >>> Group on Proximal Soil Sensing | www.researcherid.com/rid/B-4061-2011 | >>> scholar.google.com.au/citations?hl=en&user=KpJdvKEAAAAJ >>> >>> >>> >>> >>> _______________________________________________ >>> grass-user mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/grass-user >>> >> >> >> _______________________________________________ >> grass-user mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/grass-user >> > >
_______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
