Try something like this:
SELECT ST_AsEWKT(ST_PointN(ST_OffsetCurve(line1,5),ST_NPoints(line1))) as
offset_point,
ST_AsEWKT(ST_PointN(line1,ST_NPoints(line1))) as
point_10m_on_line
FROM (SELECT ST_GeometryN(ST_Split(the_line,
ST_Line_Interpolate_Point(the_line,1.0/ST_Length(the_line))),
1) as line1
FROM (SELECT ST_GeomFromEWKT('LINESTRING(25 50, 100 125, 150 190)')
as the_line ) as a
) as f;
regards
Simon
On Sat, 19 May 2012 17:34:07 +1000, Uroš Bernik <uros.ber...@siol.net> wrote:
Hello,
A question: I have a linestring (polyline) for which i would like to calculate a
point which is located on the polyline but a specific distance from the end or
beggining of the polyline. Once this point is calculated >i would then like to
calculate 2 points on both sides of the linestring, which are perpendicular to the
line like this:
[Description: cid:image001.jpg@01CD3522.C7638240]
Any idea how to do this? I didnt notice any function within postgis that deal
with stationary distances which is what im looking for probably. Thanks for any
advice!
--
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