[GRASS-user] Determining maximum value of attributes where areas are overlapping in imported vector layer

[Markus Neteler]

On Mon, Jul 7, 2008 at 6:11 PM, Rainer M Krug <r.m.krug at gmail.com> wrote:
> Hi
>
> I am back with a problem of imported shape files:
>
> I have imported a shape file and it contains several areas where
> polygons are overlapping. After I managed to obtain the number of
> overlapping polygons and exported it to a raster layer
> (http://grass.osgeo.org/wiki/Vector_Overlapping_Areas), I would now
> need the maximum value of an attribute column for this areas.
>
> Any ideas how I can achieve this?

You can use 'db.select':

echo "SELECT max(N1) FROM lidar2" | db.select
max(N1)
512834.76000000000931

Markus