[postgis-users] Interpolate Point

[sergio at labtrans.ufsc.br]

Hello again,

   My problem is the following one:  I need to interpolate a point with a
line, being that for this I possess two tables, I was trying to use the
following command:
  - SELECT line_interpolate_point(f.geom, line_locate_point(f.geom,
c.geom)) from railroad f, city c;
  Where geom of the railroad is a field MULTILINESTRING and geom of the city
is a field POINT, this command does not function, therefore the first
argument of line_locate_point must be LINE and not MULTILINESTRING, would
like to know if somebody possue some suggestion of as I can tranformar
this MULTILINESTRING in LINE or if exists some function that finds the
line next to a point and that it returns as resulted the point where the
original point is interpolated with the line.

grateful,
Sérgio Zarth Jr.