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measurements

CORE
This module contains functions that compute measurements of distance, area and angles. There are also functions to compute geometry values determined by measurements.
ST_AREA
ST_AREA(geom)
Description
If Geometry g is areal, returns the area of its surface in square units of the coordinate reference system (for example, degrees^2 for EPSG:4326). Returns 0.0 for non-areal geometries (e.g. Points, non-closed LineStrings, etc.).
geom: Geometry input geom.
Return type
Double
Example
1
SELECT carto.ST_AREA(carto.ST_MAKEBBOX(0, 0, 2, 2));
2
-- 4
ST_DISTANCE
ST_DISTANCE(geomA, geomB)
Description
Returns the 2D Cartesian distance between the two geometries in units of the coordinate reference system (e.g. degrees for EPSG:4236).
geomA: Geometry input geom A.
geomB: Geometry input geom B.
Return type
Double
Example
1
SELECT carto.ST_DISTANCE(carto.ST_POINT(0, 0), carto.ST_POINT(0, 5));
2
-- 5
ST_DISTANCESPHERE
ST_DISTANCESPHERE(geomA, geomB)
Description
Approximates the minimum distance (in meters) between two longitude/latitude geometries assuming a spherical earth.
geomA: Geometry input geom A.
geomB: Geometry input geom B.
Return type
Double
Example
1
SELECT carto.ST_DISTANCESPHERE(carto.ST_POINT(0, 0), carto.ST_POINT(0, 5)) / 1000;
2
-- 555.9753986718438 (distance in km)
ST_LENGTH
ST_LENGTH(line)
Description
Returns the 2D path length of linear geometries, or perimeter of areal geometries, in units of the the coordinate reference system (e.g. degrees for EPSG:4236). Returns 0.0 for other geometry types (e.g. Point).
line: LineString input line.
Return type
Double
Example
1
SELECT carto.ST_LENGTH(carto.ST_GEOMFROMWKT('LINESTRING(0 0, 0 3, 5 3)'));
2
-- 8
ST_LENGTHSPHERE
ST_LENGTHSPHERE(line)
Description
Approximates the 2D path length of a LineString geometry using a spherical earth model. The returned length is in units of meters. The approximation is within 0.3% of st_lengthSpheroid and is computationally more efficient.
line: LineString input line.
Return type
Double
Example
1
SELECT carto.ST_LENGTHSPHERE(carto.ST_GEOMFROMWKT('LINESTRING(0 0, 0 3, 5 3)')) / 1000;
2
-- 888.7982099954688 (distance in km)
indexing
parsers
Last modified 8mo ago