PostGIS
Synopsis
geometry +`*`+ST_LocateAlong*(`geometry `geom_with_measure,
float8 measure, float8 offset = 0`)`;
Description
Returns the location(s) along a measured geometry that have the given measure values. The result is a Point or MultiPoint. Polygonal inputs are not supported.
If offset is provided, the result is offset to the left or right of
the input line by the specified distance. A positive offset will be to
the left, and a negative one to the right.
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The semantic is specified by the ISO/IEC 13249-3 SQL/MM Spatial standard.
Availability: 1.1.0 by old name ST_Locate_Along_Measure.
Changed: 2.0.0 in prior versions this used to be called ST_Locate_Along_Measure.
This
function supports M coordinates.
This
method implements the SQL/MM specification.
SQL-MM IEC 13249-3: 5.1.13
Examples
SELECT ST_AsText(
ST_LocateAlong(
'MULTILINESTRINGM((1 2 3, 3 4 2, 9 4 3),(1 2 3, 5 4 5))'::geometry,
3 ));
----------------------------------
MULTIPOINT M ((1 2 3),(9 4 3),(1 2 3))