| lunar.distance {lunar} | R Documentation |
Lunar Distance
Description
Returns the distance of the moon from the earth on specified dates.
Usage
lunar.distance(x, shift = 0, ..., name = FALSE, strict = FALSE)
Arguments
x |
A vector of |
shift |
The number of hours by which to shift the distance calculation. By default distance is calculated at 12 noon UT. |
... |
Other optional arguments are ignored. |
name |
Optional parameter indicating whether the return is a factor variable consisting of a lunar distance label, or the lunar distance in earth radii. By default lunar phase is returned in earth radii. |
strict |
Optional parameter indicating whether the return should employ strict definitions for distance labels, that is, with apogee and perigee within 5 definition breaks the distance categories evenly into 20 The 'average' category is the same in both definitions. |
Details
Distance to the moon is returned in units of earth radii, or
as a 5-level factor variable referring to the moon's
perigee (at about 56 earth radii) and
apogee (at about 63.8 earth radii).
Adapted from Stephen R. Schmitt: Lunar Phase Computation: https://web.archive.org/web/20140716104947/http://mysite.verizon.net/res148h4j/zenosamples/zs_lunarphasecalc.html, Last accessed: 1 September 2014.
See Also
Examples
lunar.distance(as.Date("2004-03-24"))