selecting edges in vectors

[Agustin Lobo]

I'd like to do the following:
1. Assume I have a raster thematic image (land cover types).
2. I vectorise with r.poly
3. Now I would like to select those vector lines that are
boundaries between 2 given classes, i.e., lines that are
edges between type 4 and type 5.

Can this operation be done in Grass with vector files?
If not but you are bith an ArcInfo and Grass user, could this
operation be done with AI?

Thanks!

Agus

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Dr. Agustin Lobo
Instituto de Ciencias de la Tierra (CSIC)
Marti Franques s/n
08028 Barcelona (Spain)

tel. 34 3 330 2716
fax. 34 3 411 0012

alobo at ija.csic.es
alobo at eno.princeton.edu
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