[GRASS-user] Connecting vector points with the same category number

[Markus Neteler]

On Tue, Jun 15, 2010 at 12:15 PM, Aldo Clerici <aldo.clerici at unipr.it> wrote:
> Dear GRASSusers,
>
> having a vector point map with many different category values, is there a
> way to construct a vector map with lines connecting  the points with the
> same category number ?

Dear Aldo,

I think that v.in.lines should do the job (GRASS 6.5 and 7):
http://grass.osgeo.org/grass65/manuals/html65_user/v.in.lines.html

The input could be generated with v.out.ascii (Spearfish example):

v.out.ascii archsites fs=, where="cat=1 or cat= 3" | cut -d',' -f1,2
593493,4914730,1
589860,4922000,3

I have drafted a FAQ at:
http://grass.osgeo.org/wiki/Convert_points_to_lines

Markus

PS: I think that we could add this to GRASS 6.4, too (for now,
you can just download it from SVN:
http://trac.osgeo.org/grass/browser/grass/branches/develbranch_6/scripts/v.in.lines
)