[postgis-users] Purpose of mesure value in 4D geoms

[Markus Schaber]

Hi, Jeremy,

Jeremy Palmer schrieb:

> Sorry if this seems to be a simple question but could someone explain
> the use and purpose of the M value in the new lwgeom geometry structure.

You can use it for lean storage of measured values if you record geo
coded measured values. E. G. with an XYZM geometry you can record
position and height above ground and air pressure, or with an XYM
geometry you can store longitude, latitude and fuel level of a ship.

The alternative is to use plain XY(Z) geometries and store the measured
values into their own table columns.

Markus