[postgis-users] simplify

[Paul Ramsey]

The units for Simplify() are the units of the data, so yes, if you 
Simplify() decimal degrees data, you'll want to supply a decimal degrees 
tolerance.

That said, DO NOT use Simplify() on decimal degrees data unless you live 
on the equator.  The difference in scale horizontally and vertically in 
more northerly areas will result in "odd" simplifications when in 
decimal degrees.

Paul

Stephen Crawford wrote:
> One last question and I'll leave you all alone for the day :)
> 
> If I want to generalize my data, I should simplify()?  So if the data are in
> decimal degrees, then is the tolerance decimal degrees?  Something like
> this?
> 
> CREATE TABLE accipiter AS SELECT 
> 	gid,engl_name,sci_name,origin,Simplify(the_geom,0.01) as the_geom
> FROM all_species
> WHERE family='Accipitridae';

-- 

   Paul Ramsey
   Refractions Research
   http://www.refractions.net
   pramsey at refractions.net
   Phone: 250-383-3022
   Cell: 250-885-0632