[FoRK] map search
aaron at bavariati.org
Mon Mar 4 14:31:49 PST 2013
On Sat, Mar 02, 2013 at 09:53:07AM -0500, Kelley Howell wrote:
> I'm working on a new project, map-based search. Yeah, a little late
> to the part.
I did some work on store locators, typical geo application. General notes:
* Google's geolocation services are great, and free.
* Embedding a Google map in a page is a doddle.
* Addresses usually had to be cleaned up, checked for duplicates, geocoded,
and then checked for geocoding failures (again, due to bad addresses.)
* We kept bad address info around to help sanitize future updates.
* It's nice to have an interface to let clients add/update addresses
themselves. Let them deal with their own bad data.
* Never trust customer-supplied Lat/Long info.
* Simple great-circle distance calculations work great in most cases.
* Distance searches are expensive, limit your search set using simple
lat/long ranges first.
* Be careful with 50-mile-radius-plus searches. Too many matches is bad.
* Postgres has nice geo features, but we did fine without them.
* It wouldn't hurt to cache distances between common locations.
* As an end-user, it's nice to be able to pick a landmark near my location.
As usual, the tech is simple, the UI and customer interaction is hard.
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