[GRASS-user] 2D - 3D raster intersection

[Hamish]

Tomas wrote:
> >> I have a 3D raster and several 2D elevation rasters. Is it possible to
> >> perform somehow (within GRASS, or outside) intersection betwwen the 2D
> >> and 3D rasters and get 2D raster with values of the 3D rasters where
> >> they are intersected?

maybe some hints here:  http://grass.gdf-hannover.de/wiki/Help_with_3D
r3.mapcalc?


> Boris Avdeev wrote:
> > Using Matlab (or octave):
> > 
> > n=1;index=zeros(prod(dim(rast2d)),3)
> > for [i j]=1:dim(rast2d,[1 2])
> >   k=round(rast2d(i,j))
> >   index(n,:)=[i j k]
> > end
> > answer=rast3d(index)

> Boris Avdeev wrote:
> > Using Matlab (or octave):
> > 
> > n=1;index=zeros(prod(dim(rast2d)),3)
> > for [i j]=1:dim(rast2d,[1 2])
> >   k=round(rast2d(i,j))
> >   index(n,:)=[i j k]
> > end
> > answer=rast3d(index)

Tomas Lanczos wrote:
> thank You Boris, it is something new for me, how can I integrate octave 
> to grass? is there a tutorial for that?

Transfer raster maps with r.in.mat and r.out.mat. Transfer vector data with
'v.in.mapgen -f' (or v.in.ascii), and 'v.out.ascii format=standard' (plus a few
lines of matlab code).


Hamish



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