[postgis-users] 3d Points

[Christian Heine]

Hi list,
a newbie needs some advice:
I want to store min/max z values and their associated lon/lat  
obtained from regional grids in a postgis db. The values are spit out  
as zmax/zmin (in km, mW/m^2, etc), zmax/zmin_lon, zmax/zmin_lat. As  
far as I understand, one has to use GeomFromEWKT here as OpenGIS  
formats only support 2d objects.
Is it advisable to use EWKT or is it better to create an extra z- 
value column and keep the z-value separated from the lon/lat? Also,  
what is the difference between POINTM and POINT? I couldn't find any  
information explaining the "M".

Thanks a lot for the help.
Cheers from Sydney,
Christian

--
Christian Heine
ph.d. student

         USIMS       |    University of Sydney
                     |    Institute of Marine Science
                     |    Sydney, Australia

P +61 2 9351 4257   •   F +61 2 9351 0184