[Accessibility] Finding the Nearest POI

[Lulu-Ann at gmx.de]

Hi Alex,

> Let me try to explain it. I am standing near the intersection that Trekker
> calls 57 Avenueand 180 Street. I want my application, at the clickof a
> utton, to tell me this intersection is the nearest. My problem comes from the
> fact that I can't figure out howto identify the nearest POI from within my
> application.


You get the coordinates from your GPS.
You know the coordinates of some nearby POIs or intersections.

For a first guess
I would search for the 4 points that are nearest in each direction (That is an easy linear comparison with the two coordinates.
Then calculate the correct distance (you will need to find the formula for the projection)
Wikipedia might help you to start: http://en.wikipedia.org/wiki/Geographic_coordinate_system
and
http://en.wikipedia.org/wiki/World_Geodetic_System

And last, pick the one of the four that is nearest...

Hope this helps you.

Regards
Lulu-Ann
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