[postgis-users] simplify() on lat/lon data

[Tyler Mitchell]

> Theres distance-on-ellipse calculations already available in postgis - 
> see postgis_proj.c.
> You can call distance_ellipse() to give the distance-on-ellipse or you

Do you mean distance_ellipsoid which is available in pg through 
distance_spheroid?

> can call distance_sphere_method() which is much faster but less 
> accurate.  For distances in the "few meters" range, I recommend the 
> distance_sphere_method() - see the documentation for how it works.

What's a valid value for "spheroid"?

> REMEMBER: the lat/lot number have to be in radians (i.e. *M_PI/180.0).

*M_PI ?