[postgis-users] break lines at intersections

[Pedro Costa]

i found the error. the parallels are a less then 3 meters...

thanks



Em 17-05-2012 16:43, Pedro Costa escreveu:
> I'm already tried this function but with no good results, I do not 
> understand why.
> You can see an example in the attached image. The streets are red 
> lines. The parallel purple and what I want to clear yellow.
>
> Any idea ?
>
>
> I tried the st_dwithin like this:
>
>
> create table street8 as (SELECT paralell.geom FROM parallel,street 
> WHERE st_dwithin(paralell.geom, streets.the_geom, 2.99 ))
>
>
> The 'line erros' that i want to delete are a less than 3 meters from 
> streets...
>
>
> thanks
>
>
>
> Em 17-05-2012 16:32, Nicolas Ribot escreveu:
>> Yes, it should be:
>> st_dwithin will help you to find all lines from a table within a 
>> certain distance to other lines.
>>
>> Nicolas
>>
>> On 17 May 2012 17:23, Pedro Costa <pedrocostaarma at sapo.pt 
>> <mailto:pedrocostaarma at sapo.pt>> wrote:
>>
>>     Great Nicolos, works...
>>
>>     It is possible select lines from one table a less than 3 meters
>>     from lines from another table?and delete them...
>>
>>     thanks
>>
>>
>>     Em 17-05-2012 15:41, Nicolas Ribot escreveu:
>>>     Hi Pedro,
>>>
>>>     select (st_dump(st_union(geom))).geom from lines;
>>>
>>>     will cut your network of lines at intersections.
>>>
>>>     Nicolas
>>>
>>>     On 17 May 2012 11:57, Pedro Costa <pedrocostaarma at sapo.pt
>>>     <mailto:pedrocostaarma at sapo.pt>> wrote:
>>>
>>>         does anyone know how I can cut the lines at
>>>         intersectionslike the image attached?
>>>
>>>         I can´t install postgis 2.0 for now....
>>>
>>>         I see a few examples with st_union and st_dump but i don't
>>>         understand...
>>>
>>>
>>>         Thanks
>>>
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>>>
>>>
>>>
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>>
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