[GRASS-dev] barscale in latlong region

[Hamish]

Michael Barton wrote:
> 
> How about making d.barscale be approximately accurate in latlon near
> the bottom of the map and say so in the docs? Not ideal, but useable
> perhaps.


In short, no.

e.g. whole world etopo2/nasa blue marble/admin98:
 g.region n=90 s=-90 w=-180 e=180

horizontal scale at the bottom of the map (s pole) is a singularity.
even if you use the center of the region (equator) it is badly wrong
over most of the map. I though about testing to see if the region was
small enough for the scale not to change much (>1-2 pixel) over the
spread of the map, but then it is still a different scale in the x and y
dirs unless you are on the equator.


Hamish