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
***************************************************
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@ija.csic.es
alobo@eno.princeton.edu
***************************************************
Hi,
This is a bit round-a-bout, but would this work:
1) r.poly
2) v.llabel the lines
3) v.to.rast the lines
4) buffer the lines
5) r.mapcalc finallines = 'if((buffer) && (data == 4 || data == 5))'
6) r.thin the finallines
7) r.line the finallines
Rick
On Thu, 22 Feb 1996, Agustin Lobo wrote:
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?
------------------------------------------------------------------------
Rick Thompson- Research Specialist E-mail: rick@cast.uark.edu
Center for Advanced Spatial Technologies Telephone: (501) 575-6159
Ozark Hall Rm. 12 Fax: (501) 575-5218
University of Arkansas
Fayetteville, AR 72701
DISCLAIMER: Any opinions or comments about any product, organization,
or individual expressed in the above text are my own.