Hi all,<br><br>I think I've got a bit of a problem with snapping points to lines.  I had thought that using line_interpolate_point(..., line_locate_point(...)) would do the trick, but this seems not to be the case:<br>

<br>gis=# SELECT ST_AsText(v.the_geom), ST_SRID(v.the_geom), ST_AsText(r.the_geom), ST_SRID(r.the_geom) FROM road_segments AS r, venues AS v WHERE v.venue_id = 29 AND r.gid = 100982;<br><br>                st_astext                 | st_srid |                                    st_astext                                    | st_srid <br>

------------------------------------------+---------+---------------------------------------------------------------------------------+---------<br> POINT(415185.606066865 7827721.52951473) |   28353 | LINESTRING(415250.679102704 7827994.85292521,415218.694181662 7827642.44920486) |   28353<br>

(1 row)<br><br>gis=# SELECT ST_Intersects(ST_line_interpolate_point(r.the_geom, ST_line_locate_point(r.the_geom, v.the_geom)), r.the_geom) FROM road_segments AS r, venues AS v WHERE v.venue_id = 29 AND r.gid = 100982;<br>

<br> st_intersects <br>---------------<br> f<br>(1 row)<br><br>gis=# SELECT postgis_full_version();<br><br>                                  postgis_full_version                                  <br>----------------------------------------------------------------------------------------<br>

 POSTGIS="1.4.1" GEOS="3.2.1-CAPI-1.6.1" PROJ="Rel. 4.7.1, 23 September 2009" USE_STATS<br>(1 row)<br><br><br><br>Any assistance would be much appreciated.<br><br>Thanks,<br><br>-Francis Markham<br>

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