• NAME
• DESCRIPTION
• FORMULA
• SEE ALSO
• SUPPORT
• AUTHORS
• LICENSE

NAME

GIS::Distance::Cosine - Spherical law of cosines distance calculations.

DESCRIPTION

Although this formula is mathematically exact, it is unreliable for small distances. See the GIS::Distance::MathTrig manpage for related details.

A faster (XS) version of this formula is available as the GIS::Distance::Fast::Cosine manpage.

Normally this module is not used directly. Instead the GIS::Distance manpage is used which in turn interfaces with the various formula classes.

FORMULA

    a = sin(lat1) * sin(lat2)
    b = cos(lat1) * cos(lat2) * cos(lon2 - lon1)
    c = arccos(a + b)
    d = R * c

SEE ALSO

• https://en.wikipedia.org/wiki/Spherical_law_of_cosines

SUPPORT

See SUPPORT in the GIS::Distance manpage.

AUTHORS

See AUTHORS in the GIS::Distance manpage.

LICENSE

See LICENSE in the GIS::Distance manpage.