[GRASS-user] generating lines from points

[Martin Landa]

Hi,

2009/1/19 Moritz Lennert <mlennert at club.worldonline.be>:

[...]

>> v.net points=points output=net operation=net file=- << EOF
>> 1 1 2
>> 2 2 3
>> EOF
>>
>> What do you think about that?
>
> I think that a GRASS module for connecting lines between chosen points is a
> definite yes (think of point coordinates of airports with information about
> flight connections between airports). Up to now I've been doing it with a
> simple script + v.in.ascii.
>
> Not sure v.net is the most logical place to have this. Maybe a stand-alone

v.net seems to be good place. There is already tool for generating
points ('nodes'), so why not tool for generating lines (arcs/edges)?
v.net updated in GRASS7 [1].

> module v.points2lines ?

This could be more general module.

v.points? input=- output=lines type=line << EOF
1 1 2
2 2 3
3 4 5
EOF

creates separated lines

v.points? input=- output=area type=area << EOF
1 1 2
2 2 3
3 4 5
EOF

creates closed ring -> area

Note that `v.net operation=arcs` create vector map with two layes -
arcs (lines) and nodes (point).

Martin

[1] http://trac.osgeo.org/grass/changeset/35490

-- 
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *