Breaklines in interpolation

[rappold(at)zedat.fu-berlin.de]

Hi,

I'm working on a elevation model with terraces.
Does somebody know if it is possible to use "breaklines" in 
some interpolation methods (like in some GIS programs like ArcInfo).

On the one hand I want to limit the interpolation within a certain 
island (which is easy when you can "mask" the area). 
On the other hand I would like to force the interpolation at certain
points/lines to certain altitudes.

Any suggestions?

Gerhard
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Gerhard D. Rappold                       B.E.R.G.
Institute for Geo-Sciences               Berlin 
Free University of Berlin                Environmental
Malteserstr. 74-100                      Research
D-12249 Berlin                           Group
e-mail: rappold@zedat.fu-berlin.de
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