[GRASS-user] v.dissolve for lines?

[Bryan Keith]

> On 11/05/2010 09:59 PM, Bryan Keith wrote:
>>> On 10/19/2010 11:17 PM, Bryan Keith wrote:
>>>
>>>> Hello,
>>>>
>>>> I have a vector line file that has lots of two-vertex lines.  Many of
>>>> these two-vertex lines share endpoints and really just make parts of
>>>> one
>>>> longer line.  I'd like to dissolve these lines into one line when they
>>>> have the same end point.  It looks like v.dissolve only works for
>>>> areas.
>>>> Is there somewhere else I should be looking?  Thank you.
>>>>
>>>>
>>>>
>>> Did you have a look at v.build.polylines ?
>>> Additional note: line vectors have a direction. Two line segments with
>>> an equivalent node (end point) will *not* connect if they are in
>>> opposite directions. In this case you can try the v.edit tool=flip
>>> option (on those segments only)
>>>
>> Thank you for the response.  I finally got around to looking at this
>> today.  I made a simple example and tested with v.build.polylines, and
>> it
>> works great.  Thank you.
>>
>> However, it turns out that I have many duplicate lines in my dataset.  I
>> created a simple example where there are duplicate lines, and
>> v.build.polylines doesn't work in that case.  What do I need to look at
>> to
>> get rid of duplicate lines?
>>
>>
>
> v.clean tool=rmdupl
> Might do it if the lines exactly overlap.

Yes, that worked in my case.  Thanks so much, Micha!

Bryan