[thelist] Zip Code Distance From

Casey Crookston caseyc at IntelliSoftmn.com
Wed Mar 28 11:24:05 CDT 2007


>>
It looks like the Geocoder web service is free, and has C# sample code
available:

  http://geocoder.us/help/csharp.shtml<<


Ok, I'm scared:

~~~~~~~~~~~~~~~~~~
The right way to calculate distance is with spherical trig. Take a look
at this distance testing program for an example of calculating distance
in the three ways mentioned.

Assuming you have perl: perl disttest.pl lat1 long1 lat1 long2

[rich at testingrange geo]$ ./disttest.pl 45 0 55 10
spherical trig distance: 819.41783616337
cartesian distance: 975.807358037436
cosine modified cartesian distance: 820.251821885442
~~~~~~~~~~~~~~~~~~

I'm starting to think that a nice 3rd party app that costs a few $ might
be a better option.

Casey
 



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