RosettaCodeData/Task/Haversine-formula/Forth/haversine-formula.fth
Ingy döt Net db842d013d A-M baby
2013-04-10 21:29:02 -07:00

15 lines
668 B
Forth

: s>f s>d d>f ;
: deg>rad 174532925199433e-16 f* ;
: difference f- deg>rad 2 s>f f/ fsin fdup f* ;
: haversine ( lat1 lon1 lat2 lon2 -- haversine)
frot difference ( lat1 lat2 dLon^2)
frot frot fover fover ( dLon^2 lat1 lat2 lat1 lat2)
fswap difference ( dLon^2 lat1 lat2 dLat^2)
fswap deg>rad fcos ( dLon^2 lat1 dLat^2 lat2)
frot deg>rad fcos f* ( dLon^2 dLat2 lat1*lat2)
frot f* f+ ( lat1*lat2*dLon^2+dLat^2)
fsqrt fasin 127456 s>f f* 10 s>f f/ ( haversine)
;
36.12e -86.67e 33.94e -118.40e haversine cr f.