searchelite wrote: > > > > Obe, Regina DND\MIS wrote: >> >> Now you do your make line. But you'll have to take into consideration >> what Paolo Rizzi said afterward. Not sure the easiest way to do that. >> >> So basically your process should look something like the below where >> trip_id is some fied that uniquely identifies each trip. The below snaps >> each point to closest road segment and then makes a line for each trip. >> It assumes the pt.gid is in the order of time travel. If you have a >> datetime field for each point, use that instead of the pt.gid. >> >> SELECT trip_id, ST_MakeLine(snapped_point) As trip_route >> (SELECT >> pt_id, >> ln_id, >> >> ST_Line_Interpolate_Point( >> ln_geom, >> ST_Line_Locate_Point(ln_geom, pt_geom) >> ) As snapped_point, >> travel_id >> >> FROM >> ( >> SELECT DISTINCT ON (pt.gid) >> ln.the_geom AS ln_geom, >> pt.the_geom AS pt_geom, >> ln.id AS ln_id, >> pt.gid AS pt_id,pt.trip_id >> FROM >> gps_points pt INNER JOIN >> road_table ln >> ON >> ST_DWithin(pt.the_geom, ln.the_geom, 10.0) >> ORDER BY >> pt.gid,ST_Distance(ln.the_geom, pt.the_geom) >> ) AS subquery ORDER BY trip_id, pt_id) As snapped_points >> GROUP BY travel_id; >> >> Hope that helps, >> Regina >> >> > > > thanks a lot for the reply...i'll try the code you give me first thing > tomorrow...:-) > >
basically, the code you gave me just create a line from snapped points right? what about matching the route with the road? I want to make the route like the illustration below http://www.nabble.com/file/p18522213/untitled.jpg thank you -- View this message in context: http://www.nabble.com/match-line-with-road-segment-tp18479996p18522213.html Sent from the PostGIS - User mailing list archive at Nabble.com. _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
