[GRASS-user] movement direction surface in r.drain

[Margherita Di Leo]

Thanks for super quick answer,

On Tue, Jan 8, 2013 at 3:25 PM, Markus Metz
<markus.metz.giswork at gmail.com>wrote:

>
> Check if the friction map is not all zero or NULL for the second
> polygon,


the friction map within the ending polygon has everywhere value 1.


> that the DEM covers the second polygon,


it does.

that the second
> polygon was not used in any way as input for r.walk,


sure.


> that the second
> polygon is actually reachable from the first polygon in the output of
> r.walk,


Not sure how to verify that, but i digitized a random point within the
ending polygon (i placed it somewhere in the center) and i used it as
starting point for r.drain, and obtained a nice least cost path line.

and that the current region covers the second polygon.


It does.


> Also
> have a look at the direction output of r.walk.
>

Looks OK (it has values) but i'm still not sure what should i check in it.

Thanks,
madi

>
> HTH,
>
> Markus M
>
> >
> > Thanks in advance.
> >
> > Best,
> > madi
> >
> > --
> > Margherita DI LEO
> > Postdoctoral Researcher
> >
> > European Commission - DG JRC
> > Institute for Environment and Sustainability (IES). Unit H03 – FRC
> > Via Fermi, 2749
> > I-21027 Ispra (VA) - Italy - TP 261
> >
> > Tel. +39 0332 78 3600
> > margherita.di-leo at jrc.ec.europa.eu
> >
> > Disclaimer: The views expressed are purely those of the writer and may
> not
> > in any circumstance be regarded as stating an official position of the
> > European Commission.
>



-- 
Margherita DI LEO
Postdoctoral Researcher

European Commission - DG JRC
Institute for Environment and Sustainability (IES). Unit H03 – FRC
Via Fermi, 2749
I-21027 Ispra (VA) - Italy - TP 261

Tel. +39 0332 78 3600
margherita.di-leo at jrc.ec.europa.eu

Disclaimer: The views expressed are purely those of the writer and may not
in any circumstance be regarded as stating an official position of the
European Commission.
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