[GRASS-user] intersect vector line by vector point

Maciej Sieczka tutey at o2.pl
Sun Oct 1 12:50:34 EDT 2006


Maciej Sieczka wrote:
> Michaël Rabotin wrote:
>> Hi everybody, i'm a rooky on GRASS 6.01 (ubuntu) and i search a command to
>> intersect a vector line by a vector point (so the points on the lines cut
>> the lines in the output file).
>> Does anyone have a solution to threat this problem ?
> 
> Are your "points" and "lines" separate files?
> 
> If so, and the points are located exactly along the lines, try to
> v.patch the 2 files, then v.clean tool=break.

I need to achieve the same thing now, and I realized the method I
suggested above is no good - v.clean won't break lines at intersections
with points; it only breaks lines intersecting with other
lines or boundaries.

Has anybody an idea how to divide several connected lines
(watercourses) at irregulalary spaced points, located along the
watercourse they are supposed to divide, stored in a separate vector
file? Input line direction and category must be preserved in each line
segment in the output.

Otw - how to add nodes (not vertices) to the line at specified
locations, preserving the category and direction of the input line in
each resulting segment?

v. segment is not good for that purpose. Or at least I don't know how
to use it for that.

Sorry for missinforming you Michaël.

Thoughts?

Cheers,
Maciek




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