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ST_LocateAlong

ST_LocateAlong
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Name

ST_LocateAlong — Returns the point(s) on a geometry that match a measure value.

Synopsis

geometry ST_LocateAlong ( geometry geom_with_measure , float8 measure , float8 offset = 0 ) ;

Description

Returns the locations along a measured geometry (as a Point or MultiPoint) that match a measure value. Polygonal elements are not supported.

If the 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.

[Note]

Use this function only for geometries with an M component

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.

Examples 

SELECT ST_AsText(
  ST_LocateAlong(
    'MULTILINESTRINGM((1 2 3, 3 4 2, 9 4 3),(1 2 3, 5 4 5))'::geometry,
    3 ));

            st_astext
----------------------------------
 MULTIPOINT M (1 2 3,9 4 3,1 2 3)

See Also

ST_LocateBetween , ST_LocateBetweenElevations

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