[postgis-users] break lines at intersections

[Pedro Costa]

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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