<div dir="ltr"><div><div><div><div><div>I hope you are not runnning into a very annoying precision issue.<br></div>If it were the case, you may want to try the patch I just submitted to GEOS, (<a href="https://github.com/Remi-C/libgeos">https://github.com/Remi-C/libgeos</a>).<br>
<br></div>and then you would check like this : <br>decompose line A into points (ST_DumPPoints)<br>if any point is on line B : true<br></div>else <br>decompose line B into points<br></div>if any point of B in on line A<br>
return true<br>else return false<br><br></div>(you chekc "point on line" with st_intersects)<br><div><div><div><br>Cheers,<br><br>Rémi-C<br></div></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">
2013/11/22 Rémi Cura <span dir="ltr"><<a href="mailto:remi.cura@gmail.com" target="_blank">remi.cura@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div>You may try <br><a href="http://postgis.net/docs/ST_SharedPaths.html" target="_blank">http://postgis.net/docs/ST_SharedPaths.html</a><br><br></div><div>Cheers,<br><br></div>Rémi-C<br></div><div class="HOEnZb">
<div class="h5"><div class="gmail_extra"><br>
<br><div class="gmail_quote">2013/11/22 Ani Alamo <span dir="ltr"><<a href="mailto:alamo.ani@gmail.com" target="_blank">alamo.ani@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">I tried this function:<div>intersects(buffer(LINESTRING1, 0.001), buffer(LINESTRING2, 0.001))<br></div><div>Always gives me "false" result.</div><div><br></div><div>I don't know what to do!</div>
</div><div><div><div class="gmail_extra"><br><br><div class="gmail_quote">2013/11/22 Ani Alamo <span dir="ltr"><<a href="mailto:alamo.ani@gmail.com" target="_blank">alamo.ani@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">Uhm... exactly I have this linestrings:<div>LINESTRING(2.118932325 41.398745991,2.168720219 41.385631938)<br></div><div>LINESTRING(2.142346041 41.398526436,2.111181541 41.409216161)<br></div><div><br></div>
<div>
intersections gives me:</div><div>GeometryCollection: GEOMETRYCOLLECTION EMPTY<br></div><div><br></div><div>intersects gives me:</div><div>false</div><div><br></div><div>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 </div>
<div><span style="font-family:'Droid Serif',Georgia,'Times New Roman',serif;font-size:14.399999618530273px;line-height:23px">overlaps(buffer(LINESTRING</span><span style="font-family:'Droid Serif',Georgia,'Times New Roman',serif;font-size:14.399999618530273px;line-height:23px">1, 0.001), buffer(LINESTRING2, 0.001)) also gives me "false".</span><br>
</div><div><span style="font-family:'Droid Serif',Georgia,'Times New Roman',serif;font-size:14.399999618530273px;line-height:23px"><br></span></div><div><span style="font-family:'Droid Serif',Georgia,'Times New Roman',serif;font-size:14.399999618530273px;line-height:23px">Another ideas please??</span></div>
</div><div><div><div class="gmail_extra"><br><br><div class="gmail_quote">2013/11/22 James David Smith <span dir="ltr"><<a href="mailto:james.david.smith@gmail.com" target="_blank">james.david.smith@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi Ani,<br>
<br>
Have you looked into st_intersects() ? and st_intersection() ?<br>
<br>
<a href="http://postgis.refractions.net/docs/ST_Intersects.html" target="_blank">http://postgis.refractions.net/docs/ST_Intersects.html</a><br>
<br>
James<br>
<div><div><br>
On 22 November 2013 16:17, Ani Alamo <<a href="mailto:alamo.ani@gmail.com" target="_blank">alamo.ani@gmail.com</a>> wrote:<br>
> Hi!<br>
> I need a specific function to get if two linestring overlaps. e.g.<br>
> Linestring 1 is Point (0, 0) : Point (10, 0) Linestring 2 is Point (0, 0) :<br>
> Point (3, 0)<br>
><br>
> In this case I need "true" result because LineString 1 overlaps in different<br>
> points like 0,0 1,0 2,0 & 3,0. I dont need the common points, I only need if<br>
> two linestring overlaps or not. I tried with this function in postgis...<br>
><br>
> overlaps(buffer(LINESTRING1, 0.001), buffer(LINESTRING2, 0.001))<br>
> I create a buffer on both linestrings... but muy problem is some times works<br>
> better, some times not.<br>
><br>
> Can you help me please?<br>
><br>
> Thanks!<br>
><br>
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