[postgis-users] Postgis overlapping two linestrings

[Ani Alamo]

I tried this function:
intersects(buffer(LINESTRING1, 0.001), buffer(LINESTRING2, 0.001))
Always gives me "false" result.

I don't know what to do!


2013/11/22 Ani Alamo <alamo.ani at gmail.com>

> Uhm... exactly I have this linestrings:
> LINESTRING(2.118932325 41.398745991,2.168720219 41.385631938)
> LINESTRING(2.142346041 41.398526436,2.111181541 41.409216161)
>
> intersections gives me:
> GeometryCollection: GEOMETRYCOLLECTION EMPTY
>
> intersects gives me:
> false
>
> but when I see the line drawn on map I see both lines intersect in a
> little "section" (strectch). But really when I use intersects or
> intersection functions gives me "unavailable intersection"... and when I
> use OVERLAPS function
> overlaps(buffer(LINESTRING1, 0.001), buffer(LINESTRING2, 0.001)) also
> gives me "false".
>
> Another ideas please??
>
>
> 2013/11/22 James David Smith <james.david.smith at gmail.com>
>
>> Hi Ani,
>>
>> Have you looked into st_intersects() ? and st_intersection() ?
>>
>> http://postgis.refractions.net/docs/ST_Intersects.html
>>
>> James
>>
>> On 22 November 2013 16:17, Ani Alamo <alamo.ani at gmail.com> wrote:
>> > Hi!
>> > I need a specific function to get if two linestring overlaps. e.g.
>> > Linestring 1 is Point (0, 0) : Point (10, 0) Linestring 2 is Point (0,
>> 0) :
>> > Point (3, 0)
>> >
>> > In this case I need "true" result because LineString 1 overlaps in
>> different
>> > points like 0,0 1,0 2,0 & 3,0. I dont need the common points, I only
>> need if
>> > two linestring overlaps or not. I tried with this function in postgis...
>> >
>> > overlaps(buffer(LINESTRING1, 0.001), buffer(LINESTRING2, 0.001))
>> > I create a buffer on both linestrings... but muy problem is some times
>> works
>> > better, some times not.
>> >
>> > Can you help me please?
>> >
>> > Thanks!
>> >
>> > _______________________________________________
>> > postgis-users mailing list
>> > postgis-users at lists.osgeo.org
>> > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
>> _______________________________________________
>> postgis-users mailing list
>> postgis-users at lists.osgeo.org
>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20131122/bd6f863e/attachment.html>