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

G. Allegri giohappy at gmail.com
Thu Feb 19 10:05:29 EST 2009


> Can you please try GRASS 7?
> grass70/scripts/v.rast.stats/v.rast.stats.py
>
> Then we get a benchmark for the Python solution for the same
> data set.

I will try. I still haven't built GRASS 7 but this can be a good occasion.
Anyway as I can see Glynn has rewritten the same method (r.mapcalc and
r.univar).
I confirm that

v.to.rast -> (r.mapcalc to multiply/round FCEDD/DCELL to CELL) ->
r.statistics -> (r.mapcalc to FCELL/DCELL again) -> r.to.vect -> join
original vector to the output one

is absolutely the faster way. I will investiagate to make r.statistics
support float and double, then we have to join the tables and this can
be done with python (like ftools in QGIS), as GRASS7 scripting is
moving in that direction.


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