Haversine formula: Difference between revisions
→{{header|FutureBasic}}
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Since it was trivial, this functions returns the distance in miles and kilometers.
<lang futurebasic>window 1
local fn Haversine( lat1 as double, lon1 as double, lat2 as double, lon2 as double, miles as ^double, kilometers as ^double )
earth_radius_miles = 3959.0 // Radius of the Earth in miles▼
earth_radius_kilometers = 6372.8 // Radius of the Earth in kilometers▼
deg2rad = Pi / 180 // Pi is predefined in FutureBasic▼
▲ earth_radius_miles = 3959.0 // Radius of the Earth in miles
dLat = deg2rad * ( lat2 - lat1 ) ▼
▲ earth_radius_kilometers = 6372.8 // Radius of the Earth in kilometers
dLon = deg2rad * ( lon2 - lon1 ) ▼
▲ deg2rad = Pi / 180 // Pi is predefined in FutureBasic
a = sin( dLat / 2 ) * sin( dLat / 2 ) + cos( deg2rad * lat1 ) * cos( deg2rad * lat2 ) * sin( dLon / 2 ) * sin( dLon / 2 ) ▼
c = 2 * asin( sqr(a) ) ▼
miles.nil# = earth_radius_miles * c▼
▲ a = sin( dLat / 2 ) * sin( dLat / 2 ) + cos( deg2rad * lat1 ) * cos( deg2rad * lat2 ) * sin( dLon / 2 ) * sin( dLon / 2 )
kilometers.nil# = earth_radius_kilometers * c▼
▲ miles.nil# = earth_radius_miles * c
▲ kilometers.nil# = earth_radius_kilometers * c
end fn
fn Haversine( 36.12, -86.67, 33.94, -118.4, @miles, @kilometers )
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print "Distance in kilometers between BNA LAX: "; using "####.####"; kilometers; " km."
HandleEvents</lang>
Output:
<pre>
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