On Mon, Oct 24, 2016 at 4:34 PM, Anna Petrášová <[email protected]> wrote: > On Mon, Oct 24, 2016 at 10:22 AM, Phil Burgdorf <[email protected]> wrote: >> Hi Anna, >> thanks for your answer. I've tried to use 3600 as max. Cost but the >> algorithm failed. > > That's weird. > >> The values for min and max for the cummulative cost are "nan". But I don't >> know why!
This is most probably a problem of the computational region not set to the input elevation. Also, the grid geometry (extents and resolution) of the friction raster must match the elevation raster. Compare g.region -p with r.info of the input elevation and input friction. Markus M >> How can I do this in r. mapcalc. I haven't used it before > > > r.mapcalc "time_to_walk_limited = if(time_to_walk < 3600, time_to_walk, > null())" > > Please keep the discussion on the mailing list. > > >> Phil >> >> Gesendet: Montag, 24. Oktober 2016 um 16:02 Uhr >> Von: "Anna Petrášová" <[email protected]> >> An: "Phil Burgdorf" <[email protected]> >> Cc: "GRASS user list" <[email protected]> >> Betreff: Re: [GRASS-user] r. walk and sites which can be reached in a >> certain time >> On Mon, Oct 24, 2016 at 7:52 AM, Phil Burgdorf <[email protected]> wrote: >>> Hello there, >>> my name is Phil and I'm a PhD Student in Archaeology and I'm analiesing a >>> small area in bavaria. I'm trying to locate archaeological sites round >>> different strating points. Therefor I created a cost map using r. walk. >>> The >>> result is fine but how can I adapted my values. Actualy I'm interrested in >>> sites which can be reached in, let's say, one hour. I've tried to change >>> the values for max costs but I didn't get any results. Do i have to use a >>> nother algorithm? here must be an easy way to define the max cost for that >>> analysis. >>> >>> I couldn''t find any help in the mailing list's archive and I#m totally >>> lost. Can you help me? >> >> max_cost will do the trick, don't forget that the time is in seconds. >> You can also use raster algebra (r.mapcalc) to extract the area within >> certain time. >> >> Anna >> >>> >>> Cheers >>> Phil >>> >>> >>> _______________________________________________ >>> grass-user mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/grass-user >> > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
