GIS::Distance::Cosine - Spherical law of cosines distance calculations.
Although this formula is mathematically exact, it is unreliable for small distances. See GIS::Distance::MathTrig for related details.
A faster ( XS ) version of this formula is available as GIS::Distance::Fast::Cosine.
Normally this module is not used directly. Instead GIS::Distance is used which in turn interfaces with the various formula classes.
a = sin(lat1) * sin(lat2)
b = cos(lat1) * cos(lat2) * cos(lon2 - lon1)
c = arccos(a + b)
d = R * c
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<https://en.wikipedia.org/wiki/Spherical_law_of_cosines> |
See " SUPPORT" in GIS::Distance.
See " AUTHORS" in GIS::Distance.
See " LICENSE" in GIS::Distance.