astronomyengine: R Bindings to the 'Astronomy Engine' C Library

Provides access to the 'Astronomy Engine' C library () by Don Cross. The library calculates positions of the Sun, Moon, and planets, and predicts astronomical events such as rise/set times, lunar phases, equinoxes, solstices, eclipses, and transits. It is based on the 'VSOP87' planetary model and is accurate to within approximately one arcminute. This package bundles the single-file C source so that other R packages can link against it via 'LinkingTo' without shipping their own copy.