[GRASS-user] r.water.outlet and SELECT WHERE Maximum

Jachym Cepicky jachym.cepicky at gmail.com
Wed Mar 4 02:18:27 EST 2009

achim píše v Út 03. 03. 2009 v 17:52 +0100:
> Hello,
> today I have two questions...
> No 1.
> r.water.outlet doesn't produce the hole outlet. I chose coordinates E
> and N from point coordinates. The point was converted from a raster-cell
> via r.to.vect. For illustration I attach a screenshot.

IMHO, this is caused by rough raster resolution. You have to click to
some other place in order to get outlet you ar looking for

> No 2.
> I'd like to select the raster-cell with the highest value. I converted
> the raster to points and tried to select with SELECT WHERE. How can I
> use an maximum-statement in it? I couldn't fix it out. Or is there
> another way? (I use the default db)

something like SELECT cat FROM points WHERE z = (SELECT max(z) FROM

However, I'm afraid, this is not possible with DBF driver, you'll have
to convert the database e.g. into postgresql or sqlite

Jachym Cepicky
e-mail: jachym.cepicky gmail com
URL: http://les-ejk.cz
GPG: http://les-ejk.cz/pgp/JachymCepicky.pgp

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