Name
ST_AddMeasure — Interpolates measures along a linear geometry.
Synopsis
geometry ST_AddMeasure(geometry geom_mline, float8 measure_start, float8 measure_end);
Description
Return a derived geometry with measure values linearly interpolated between the start and end points. If the geometry has no measure dimension, one is added. If the geometry has a measure dimension, it is over-written with new values. Only LINESTRINGS and MULTILINESTRINGS are supported.
Availability: 1.5.0
This function supports 3d and will not drop the z-index.
Examples
Code
SELECT ST_AddMeasure( 'LINESTRING(1 0,2 0,4 0)', 1, 4) As ewelev;
Output
LINESTRING M (1 0 1,2 0 2,4 0 4)
Figure
Code
SELECT ST_AddMeasure( 'LINESTRING(1 0 4,2 0 4,4 0 4)', 10, 40) As ewelev;
Output
LINESTRING ZM (1 0 4 10,2 0 4 20,4 0 4 40)
Figure
Code
SELECT ST_AddMeasure( 'LINESTRINGM(1 0 4, 2 0 4, 4 0 4)', 10, 40) As ewelev;
Output
LINESTRING M (1 0 10,2 0 20,4 0 40)
Figure
Code
SELECT ST_AddMeasure( 'MULTILINESTRINGM((1 0 4, 2 0 4, 4 0 4),(1 0 4, 2 0 4, 4 0 4))', 10, 70) As ewelev;
Output
MULTILINESTRING M ((1 0 10,2 0 20,4 0 40),(1 0 40,2 0 50,4 0 70))
Figure