[GRASS-stats] How to give projection to polygons and calculate area

[Hamish]

Nicolás wrote:
> I am working with GRASS functions in R batch job:
> I need to calculate areas from polygons which are in a
> geographical projection. To do so, i would like to define a new
> projection (Lamert Azimutal Equal Area) to my polygons, and the
> to calculate areas.

raster areas or vector areas?

(GRASS's r.* modules generally deal with that and give the
correct area in sq-meters automatically, so no need to reproject;
the v.* modules generally/often do not [yet])

if you'd like to make a new location in GRASS via a script,
you can use the g.proj module to do that (-c flag), then use
a GRASS_BATCH_JOB to automatically pull the vector map in with
v.proj and do the calculation.


Hamish