[GRASS-user] v.what.rast sampling cells 5 km to east

[Michael Spencer]

How odd! Thanks very much for your help, will have a look at the location
I'm using and fix.

Thanks again,
Michael


On 11 July 2013 09:34, Markus Metz <markus.metz.giswork at gmail.com> wrote:

> On Mon, Jul 8, 2013 at 6:43 PM, Michael Spencer
> <spencer.mike.r at gmail.com> wrote:
> > Hi,
> >
> > I've a problem with the v.what.rast tool. I imported a vector grid of
> points
> > with a spacing of 5 km (v.in.ogr) to GRASS, along with 12 rasters
> > (r.in.arc). There is a point in the centre of each raster cell, with some
> > extra points as a buffer around the edge (still on a 5 km grid).
> >
> > Having added extra columns to the point vector file I ran v.what.rast to
> > extract the value of the 12 rasters, in turn, at each point location.
> >
> > Checking the result in the GRASS viewer the tool has appended data from
> the
> > raster cell 5 km to the east at all locations.
>
> It seems that the current region is not properly aligned to the raster
> and instead shifted by exactly half a cell in east-west direction,
> which would explain the observed results. Try to run g.region -p
> align=<raster_to_query> before using v.what.rast.
>
> HTH,
>
> Markus M
>
> >
> > Is this a bug? Has anyone else experienced it? And most importantly -
> does
> > anyone know how to fix it?!
> >
> > Ta,
> > Michael
> >
> > _______________________________________________
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> > grass-user at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/grass-user
> >
>
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