planet {moonsun} | R Documentation |
This function computes equatorial coordinates for inner or outer planet for given Julian Day Number.
planet(jday = jd(), name = "", inner = FALSE, tp, ep, oo, e, a, i, om, th, mag)
jday |
Julian Day Number, default today |
name |
name of a planet (appended to dates in result) |
inner |
TRUE if it is inner, FALSE if outer planet |
tp |
period of a planet (tropical years) |
ep |
longitude at epoch 1990 January 0.00 (degrees) |
oo |
longitude of the perihelion (degrees) |
e |
eccentricity of the orbit |
a |
semi-major axis of the orbit (AU) |
i |
inclination of the orbit (degrees) |
om |
longitude of the ascending node (degrees) |
th |
angular diameter at 1 AU (arcsecs) |
mag |
visual magnitude at 1 AU |
The algorithm used here is fairly simple, it does not consider the Kepler equation, nor gravitational influences from other planets. See sun() for details.
This function is not called by user unless calculating a position for planetoid or modified data. The planets() function calls it with appropriate parameters automatically.
An object of class eqc, containing position and other data for requested days, see planets() for details.
Lukasz Komsta
planets()