[GRASS-user] How to delete deadends?

[Patrick_schirmer]

Hi Maris,

Attached you'll find an example as shp and a picture. I search for the 
lines that is highlighted in the picture,  which are the only ones 
connected to more then one line.
My approach would be to create points out of endpoints, buffer endpoints 
and count points per buffer, but I can't import v.vect.stats, as stated 
in the other post.

Would be great if you or someone else in the list had an idea which 
works on GRASS 6.4.

greetz,

Patrick



On 11/17/2010 09:57 AM, Maris Nartiss wrote:
> Hello,
> can You, please, send in a graphical example or put for download
> sample data set?
>
> Maris.
>
>
> 2010/11/15, Patrick_schirmer<patrick_GIS at gmx.ch>:
>    
>> Thanks Markus and Hamish,
>>
>> Unfortunately v.clean rmdangle will not work for me. With Threshhold<0
>> it deletes more or less all lines, otherwise none. I guess it is because
>> the "nests" of lines consist of 4-20 lines and are all seperated from
>> each other.
>> Per defintion a line "is considered to be a dangle if no other line of
>> given /type/ is on at least one end node" (documentation v.clean
>> rmdangle). As I am searching for lines that have exactly one line as sum
>> of all connecting node, this tool doesn't help.
>>
>> I will try to solve the problem by creating points out of the line
>> (nodes), buffering the points and delete the ones intersecting only one
>> line. But I still hope that there is a more direct solution to delete
>> the line as a geometry.
>>
>> So if there are any other suggestions I would be happy about.
>> I'll keep you up to date in case I find a solution.
>>
>> Cheers, Patrick
>>
>>
>>
>> On 11/12/2010 09:51 PM, Hamish wrote:
>>      
>>> Patrick_schirmer wrote:
>>>
>>>        
>>>> I have a lot of lines that are linked to another
>>>> forming various nets. Several of those lines are
>>>> deadends. Now I search for a option to delete
>>>> "dead-ends" within those networks. It would be
>>>> perfect to delete the lines, or to search for the
>>>> nodes that link to more than one line.
>>>> I was searching in v.generalize, v.net,
>>>> v.to.point, v.to.db but won't find the proper
>>>> approach.
>>>>
>>>>          
>>> not a v.net specific thing, but in general for
>>> vector maps you can use v.clean to remove (or isolate)
>>> line "dangles" with the 'rmdangle' (or 'chdangle')
>>> tools.
>>>
>>>
>>> maybe that helps,
>>> Hamish
>>>
>>>
>>>
>>>
>>>
>>>
>>>        
>>
>>      
>    

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