Name

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

Synopsis

geometry ST_LocateAlong(geometry ageom_with_measure, float8 a_measure, float8 offset);

Beschreibung

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.

[Note]

Use this function only for linear geometries with an M component

The semantic is specified by the ISO/IEC 13249-3 SQL/MM Spatial standard.

Verfügbarkeit: 1.1.0 über die alte Bezeichnung ST_Locate_Along_Measure.

Änderung: 2.0.0 In Vorgängerversionen als ST_Locate_Along_Measure bezeichet. Der alte Name ist überholt und wird in der Zukunft entfernt ist aber noch verfügbar.

This function supports M coordinates.

This method implements the SQL/MM specification.

SQL-MM IEC 13249-3: 5.1.13

Beispiele

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))

Siehe auch

ST_LocateBetween, ST_LocateBetweenElevations, ST_InterpolatePoint