[postgis-users] find nearest point on line where distance to point not on line is minimum - or lets say drop a perpendicular on the nearest line through a given point

hi, I try to find a way to solve this problem in postgis. I have a table with lines an coorindates of a point that needn't to be on a line. I try to find 1. the id of the line wich is nearest to the point 2. get the coordinates of the point on the line which is nearest to the point

Re: [postgis-users] find nearest point on line where distance to point not on line is minimum - or lets say drop a perpendicular on the nearest line through a given point

hi, i think you're searching this: http://pgrouting.postlbs.org/wiki/LoadingtheCode4 bye 2009/10/16 Marco Lechner - FOSSGIS e.V. marco.lech...@fossgis.de hi, I try to find a way to solve this problem in postgis. I have a table with lines an coorindates of a point that needn't to be on a

Re: [postgis-users] find nearest point on line where distance to point not on line is minimum - or lets say drop a perpendicular on the nearest line through a given point

Hi Mehmet, thank you. This seems to be much faster then my experiments combining line_locate_point() and line_interpolate_point() in subselects. The main problem is now, that i have a bunch of lines (not just one specific) in a table and I want the point to be calculated on the nearest line. The

Re: [postgis-users] find nearest point on line where distance to point not on line is minimum - or lets say drop a perpendicular on the nearest line through a given point

Marco, I think what you want is something like this http://blog.cleverelephant.ca/2008/04/snapping-points-in-postgis.html The key is you want to use ST_DWithin and come up with a distance that is longer than any 2 closest lines. This will weed out a lot of falses with a spatial index so should