[GRASS-user] Problem with slope modeling .

[Radomir]

Dnia 01-05-2007, wto o godzinie 21:23 +1200, Hamish napisał(a):
> Radomir wrote:
> > The r.surf.contour methods gives much worse results then RST (see the
> > Elevation graph).
> 
> r.surf.contour will only work with interger values (so far).
> can you try something like:
> 
> r.mapcalc "map10000= int(map * 10000)"
> r.surf.contour in=map10000 out=map10000_rsc
> r.mapcalc "map_rsc = map10000_rsc / 10000.0"
> 
> then you can produce a smoother result in spite of r.surf.contour's
> limitations.
> 
I did as you suggested:
r.mapcalc "izolinie_rsc_izolinie_10k = int(izolinie_rsc_izolinie
*10000)"
r.surf.contour input=izolinie_rsc_izolinie_10k output=wysokosci_rsc_10k
r.mapcalc "wysokosci_rsc_male = wysokosci_rsc_10k / 10000.0"
then:
r.slope.aspect
and again I have those "waves" between each isoline....
See picture:
http://mort.no-ip.org/grass/indexgrass2.html

hmmm. Maybe there is something wrong with my whole project??
Basics about the project:
projection: 0 (x,y)
zone:       0
north:      444979.06151534
south:      438995.17651068
west:       597964.6049651
east:       604980.31251938
nsres:      1.26992466
ewres:      1.27004119
rows:       4712
cols:       5524
cells:      26029088
Elevation isolines are every 2.5m. Original map scale 1:10000.  

> 
> > It was really interesting to analyse the output vector map. It seems
> > that when the distance between two isolines is "large" GRASS "puts the
> > next isoline" very close to the previous and this is how the "waves"
> > comes from.
> 
> Could you specify the module name, not just "GRASS 'puts the next
> isoline'"? GRASS is the whole, there are many different methods within
> its modules, not just one, so it's hard to know which one you mean to
> refer to.
> 
> 
> Hamish

-- 
Radomir 

----
The Future Is Now ;)