[GRASS-user] Interpolation with faultlines?

[Moritz Lennert]

On 21/02/08 20:42, Maciej Sieczka wrote:
> Moritz Lennert pisze:
>> On 13/02/08 18:40, G. Allegri wrote:
>>> It's the same question I was going to ask. It would be an important
>>> advance in Grass, as I'm obliged to use commercial sw to do it (Esri)
>>> both to interpolate with barriers and to do 3D TINs with constraints.
> 
>> The answer was (and as far as I know still is) to either run 
>> v.surf.rst several times, once for each part within fault lines (using 
>> mask) or to use r.surf.nnbathy (AddOns).
> 
> r.surf.nnbathy does not support fault lines either.

Ah, ok. Sorry, my bad memory ;-)

> 
> FWIW, there is surfit [1] (FOSS). It supports fault lines AIUI - linear 
> features which don't have a value assigned, but only depict a curve at 
> which the interpolation should break. They call break/fault lines 
> "inequalities". I still haven't used surfit, but from examples [2] it 
> seems interesting.

It definitely looks interesting and as it is a tcltk library, it should 
be very easy to integrate this into a grass script module à la 
r.surf.nnbathy, i.e. export GRASS data to ascii, import into surfit and 
create surface, export to ascii and import into GRASS.

Moritz