Return the spatial reference identifier

SRID(tpoint) → integer

SELECT SRID(tgeompoint 'Point(0 0)@2001-01-01');
-- 0

Set the spatial reference identifier

setSRID(tpoint) → tpoint

SELECT asEWKT(setSRID(tgeompoint '[Point(0 0)@2001-01-01, Point(1 1)@2001-01-02)', 4326));
-- SRID=4326;[POINT(0 0)@2001-01-01, POINT(1 1)@2001-01-02)

Transform to a different spatial reference

transform(tpoint,integer) → tpoint

transform(tpoint,pipeline text,to_srid integer,is_forward bool=true) → tpoint

The transform function specifies the transformation with a target SRID. An error is raised when the input temporal point has an unknown SRID (represented by 0).

The transformPipeline function specifies the transformation with a defined coordinate transformation pipeline represented with the following string format: urn:ogc:def:coordinateOperation:AUTHORITY::CODE. The SRID of the input temporal point is ignored, and the SRID of the output temporal point will be set to zero unless a value is provided via the optional to_srid parameter. As stated by the last parameter, the pipeline is executed by default in a forward direction; by setting the parameter to false, the pipeline is executed in the inverse direction.

SELECT asEWKT(transform(tgeompoint 'SRID=4326;Point(4.35 50.85)@2001-01-01', 3812));
-- SRID=3812;POINT(648679.018035303 671067.055638114)@2001-01-01

WITH test(tpoint, pipeline) AS (
  SELECT tgeogpoint 'SRID=4326;{Point(4.3525 50.846667 100.0)@2001-01-01,
    Point(-0.1275 51.507222 100.0)@2001-01-02}',
    text 'urn:ogc:def:coordinateOperation:EPSG::16031' )
SELECT asEWKT(transformPipeline(transformPipeline(tpoint, pipeline, 4326),
  pipeline, 4326, false), 6)
FROM test;
/* SRID=4326;{POINT Z (4.3525 50.846667 100)@2001-01-01,
   POINT Z (-0.1275 51.507222 100)@2001-01-02} */