SV: SV: SV: [GRASS-user] Vector map text legend (now more spesific about logarithmic raster legend)

[Martin Album Ytre-Eide]

In my case, I am looking for a way to get a logarithmic legend and thought that I might use categories for this.
You can set the r.colors -g to get logarithmic scaling of your map, but the legend will still be linear. - I can not get a logarithmic legend. I can do r.macalc log_map=log(map,10) and get a legend with values I would have to do 10^x to get the numerical value - so for now I use gimp to change the values 1,2,3 to 10,100,1000. -but I wish there was another way....

Martin

-----Opprinnelig melding-----
Fra: Moritz Lennert [mailto:mlennert at club.worldonline.be] 
Sendt: 25. mai 2011 10:05
Til: Martin Album Ytre-Eide
Kopi: 'Hamish'; grass-user at lists.osgeo.org
Emne: Re: SV: SV: [GRASS-user] Vector map text legend (now more spesific about logarithmic raster legend)

On 23/05/11 15:34, Martin Album Ytre-Eide wrote:
> I think Arc&  copycats use class breaks so much in their legends 
> simply as a matter of the vector-feature heritage of that software; 
> histogram classes make more sense if you start with a number of sparse 
> data points. In raster maps (traditionally GRASS's strong
> point) it is more a case of continuous gradations. shrug; just a small 
> theory.

Classification of data into a limited number of categories is always about reduction of information for ease of interpretation. Yes, you can "lie with maps", but at the same time a series of treatments of information become much easier with a reduced set of categories (e.g. 
comparison of situation over time and space).

Definitely an interesting debate. But even the author of "How to Lie with Maps" does not put into question the use of categories in maps...

Moritz