[GRASSLIST:7572] Interior Buffers

[Dave Sampson]

using r.buffer how might I perform an interior buffer. That is take the 
outside of a raster clump (from r.clump) and make concentric internal 
buffers at 100, 200, 300 meters etc?.

The use is determining a wheighted score for habitat sensitive to edge 
disturbances.... check out 
http://www.udel.edu/johnmack/frec682/682proj2.html  right at the end, 
fourth paragraph from the bootom.

this would be a benifical discovery. I thought of using a centroid and 
buffering out from that, but that is not accurate for the EDGE distaurbance

I tried using -100,-200 (no quotes) etc and also '-100' (single quote) 
and "-100" (double quote). No mention in the MAN pages of 6.0 or past 
versions.

Crucials:
Cygwin GRASS 6.1 CVS through Cygwin install
windows XP

don't imagine it is something on compiling as its a process that should 
be inherent somewhere.

Thanks

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