[GRASS-user] Re: Points buffering without dissolve query (Roy
rchirgwin at ozemail.com.au
Mon Nov 22 14:34:25 EST 2010
> Message: 3
> Date: Mon, 22 Nov 2010 09:53:57 +0000
> From: Roy Sanderson<r.a.sanderson at newcastle.ac.uk>
> Subject: [GRASS-user] Points buffering without dissolve query
> To:grass-user at lists.osgeo.org
> Message-ID:<4CEA3DB5.8010902 at newcastle.ac.uk>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> Dear All
> I have someone with a GRASS map of several thousand points which we wish
> to buffer around each point 1km, but without dissolving buffer circles
> into each other (some points are less than 1 km apart). Then we plan to
> overlay the buffers onto a raster map, and extract the raster cell
> composition information within each buffer into a separate file
> (rows-sites; columns-raster categories within each buffer).
> Unfortunately, this should ideally work on a Windows version of GRASS
> (end-user request), although as I use Linux this may still provide a
> solution otherwise.
> I would be grateful for any advice on the appropriate method (GRASS 6.4)
> Many thanks
When v.buffer was re-written, someone removed the "debug=buffer" option
which would have given you exactly what you wanted.
However, if you are on Linux, there is a solution. Go to the source of
an older version, even one of the early 6.4 release candidates, and get
the source code of v.buffer.
You can give it a new name - I use v.oldbuffer - and compile it as this.
You can then run it as v.oldbuffer and use debug=buffer to get the
"undissolved" output. I use this quite frequently when I have a very
large number of overlapping buffers, because Grass can stall when it's
trying to clean the output.
More information about the grass-user