I have to also step in here. PostGIS is a great tool but it can't teach
you basic GIS concepts if people won't take the time to learn them. To
work in mapping and GIS you have to have at least a concept of
coordinate systems and projections. Otherwise anything you develop will
still cause confusion for those who don't understand GIS but can grab
big sets of data and put it into PostGIS as Paul states below.
The original question could be phrased as follows:
"I have a big spreadsheet table of the heights of students in my class.
When I use the spreadsheet function =AVERAGE(...) what units is the
average in?"
or:
"I have a big spreadsheet table of the heights of students in my class.
The values are mixed between cm, inches, and decimal feet. Why am I not
getting the correct answer for AVERAGE()?"
Bruce
Paul Ramsey wrote:
The danger of this approach is that it falls apart as people start
pushing the limits...
select blah from a, b where st_dwithin(st_utm(a.geom),st_utm(b.goem),100)
It's a pandora's box... as are all things geodetic
p
_______________________________________________
postgis-users mailing list
[email protected]
http://postgis.refractions.net/mailman/listinfo/postgis-users
