Re: Radius of a zip code

On Fri, Dec 26, 2003 at 19:42:44 -0700, Michael Fuhr <mike@fuhr.org> wrote:
> 
> I have several databases with lat/lon coordinates and frequently make
> "show me all records within a certain distance of this point" queries.
> I wrote a haversine() function that uses the Haversine Formula to
> calculate the great circle distance between two points on a sphere
> (assuming the earth is a perfect sphere is accurate enough for my uses).
> Here's a web site with related info:

The distance operator in contrib/earthdistance got changed to use
haversine instead of the naive formula in 7.3. In 7.4 it also provides
some functions that work with contrib/cube that allow for indexed
searches.