[GRASS-user] Joining vectors by location

daniel mcinerney daniel.o.mcinerney at gmail.com
Mon Nov 21 10:23:29 EST 2011

Hi Daniel,

According to the documentation of [1] and previous discussions [2],
v.rast.stats2 should be a lot faster.

You should be able to change the BASECOLS variable in the script
to only output the sums, which might speed things up for you.

Hope that helps.


[1] http://grass.osgeo.org/wiki/GRASS_AddOns#v.rast.stats2

On Mon, Nov 21, 2011 at 4:10 PM, Daniel Lee <lee at isi-solutions.org> wrote:

> Hi Daniel,
> Very cool name :)
> You should use v.rast.stats [1] as it "Calculates univariate statistics
>> from a raster map based on
>> vector polygons and uploads statistics to new attribute columns. " Should
>> be a more straight
>> forward approach.
> Thanks for the tip, but  v.rast.stats gives me all univariate statistics
> and takes a really long time (hours vs. seconds). I've got so many pixels
> that I get segmentation failures and in the end I only want the sums for
> each polygon. It also makes it a pain to delete the unneeded columns from
> the vector table afterwards. Or is there a way to only have v.rast.stats
> give me the sums?
> Thanks,
> Daniel
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