See the section on linear referencing (sec. 6.2.7).
(http://postgis.refractions.net/docs/ch06.html#id2775904)
You'll need to use two methods.
ST_line_locate_point(LineString, Point) returns the percentage along the
the LineString the closest point will occur.
ST_line_interpolate_point(linestring, location) returns the geometric
point given a LineString and a percentage along.
SELECT ST_line_interpolate_point(line_geom,
ST_line_locate_point(line_geom, point_geom))
FROM ...
Cheers,
Kevin
sylvain dubouis wrote:
hello, I have a point and a line.
I'd like to know the nearest point on the line from the point.
but I don't find any function to do this... is there one?
thanks for your help.
Sylvain
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