[GRASS-user] improve v.rast.stats speed?

[Giovanni Pasini]

G. Allegri ha scritto:
> Thanks for the ideas.
> I've just tried Starspan but it's performance is still too slow. I've
> let it run for 15 minutes...
> 
> r.statistics is probably the best solution. I've investigated the
> ArcGIS method and it actually seems to use a similar method
> (ratserization of the features and various automations to join the
> results). In fact they call the module "zonal statistics" that is
> generally a set of raster basded methods.
> 
> the only limitation of the actual r.statistics is that it works only
> with CELL and not float. Ok, I can multiply my values and convert to
> CELL, but we could try to let r.statistics deal with floats too...
> 

see flags on r.statistics:

-c Cover values extracted from the category labels of the cover map

Setting the -c flag the category lables of the covering raster layer 
will be used. This is nice to avoid the GRASS limitation to interger in 
raster maps because using category values floating point numbers can be 
stored. [1]


[1] http://grass.itc.it/grass63/manuals/html63_user/r.statistics.html

Ciao,
giovanni