CrsUnit

Unit functions CrsUnit

syntax

• CrsUnit(spatial_reference, unit)

definition

CrsUnit(spatial_reference, unit) results in a unit that expresses exactly what unit expresses (metric, projection, range) and additionally carries spatial_reference (e.g. 'EPSG:28992') as its coordinate reference system.

It makes the CRS a first-class component of a unit instead of a packed part of a base-unit symbol. The GeoDMS engine itself emits this operator in unit key expressions; in configurations it can be used to stamp a CRS onto a constructed point unit.

Available since GeoDMS 20.13.

example

unit<fpoint> base := range(fpoint, point_yx(0f, 0f), point_yx(10f, 10f));
unit<fpoint> crs  := CrsUnit('EPSG:28992', base);

PropValue(crs, 'SpatialReference') results in 'EPSG:28992'; data items expressed in crs behave as if expressed in base.

see also

• BaseUnit
• SpatialReference