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Message Posted: Fri, 27 May 2005 @ 13:54:52 GMT

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Yep.

     select (sin((lat2 - lat1)/2.0)**2) + (cos(lat1) * cos(lat2) * sin((long2 - long1)/2.0)**2) as A,

             7917.53141 * atan2( sqrt(1.0-a), sqrt(a) ) as dist from wherever....;

7917.53141 = the mean volumetric radius of the earth from NASA, converted to miles and multiplied by 2.

There are some gotchas here: (1) all latitudes and longitudes must be in radians; (2) be sure to divide by 2.0, not 2, because you don't want it to truncate; (3) the arguments to atan2 in Teradata are the reverse of what they are in C (why, Lord, why?).

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