This topic describes the ST_InterpolatePoint function. This function returns the m coordinate of the closest point in a geometry object to a point object.

Syntax

float8  ST_InterpolatePoint(geometry  line , geometry  point);

Parameters

Parameter Description
line The LineString object that you want to specify.
point The point object that you want to specify.

Description

This function supports 3D objects and does not delete z coordinates.

Examples

SELECT ST_InterpolatePoint('LINESTRING M (0 0 0, 2 0 2)', 'POINT(1 1)');
 st_interpolatepoint
---------------------
                   1
(1 row)