Re: Find a location given approximate latitude and longitude near the location

> I have a gps-related Oracle problem that I can use some help with.
>
> Here is the scenario that I am trying address in Oracle 8.1.7.4:
>
> I have the following tables with latitude and longitude stored in
decimal
> degrees:
>
> 1. Bus stops along with their exact latitude and longitude.
> 2. Bus riders along with the approximate latitude and longitude of
where
> they boarded a bus. I cannot assume that I will have the exact
> coordinates, only a reasonably close approximation.
>
> Can anyone help me with a solution that, given the latitude and longitude
> where a rider boarded, will return the bus stop where they boarded? The
> coordinates where the rider boarded will be guaranteed to be within a
specified
> distance of the bus stop latitude and longitude.
>
> This problem is outside the day-to-day programming issues that I normally
deal
> with and I am woefully deficient in the math department. I'm totally at a
loss
> as to where to begin, so specific calculations, formulas, sql and/or
PL/SQL code
> will earn you my vote for a spot in heaven. :) In any case, ANY help or
advice
> on how to proceed is much appreciated.
>

There are lots of nuances, such as finding the nearest neighbor of various candidates that may fall within the allowed epsilon. My advice is that it would be a lot faster to simply buy a tool that does all this for you. If you are doing this on a one-time basis, consider Manifold. At $245 it will do all this for you and allow you to use elementary spatial SQL. See http://www.manifold.net

Cheers,

Dimitri Received on Tue Nov 25 2003 - 11:45:17 CST