| angle2hms {oce} | R Documentation |
Convert Astronomical Angle in Degrees to Hours, Minutes and Seconds
Description
The purpose of angle2hms is to facilitate comparison of
rightAscension angles computed by sunAngle() and moonAngle()
with angles reported in astronomical sources and software, which
often employ an hour-minute-second notation. In that notation,
decimal hour is computed as 24/360 times the angle in degrees,
and from that decimal hour are compute integer hour and minute
values, plus a decimal second value. It is common in the
astronomical literature to use strings to represent the results,
e.g. with 11^h40^m48^s.10 for the
value used in the “Examples”; see Chapter 1 of
Meeus (1991) for more on angle calculation and representation.
Usage
angle2hms(angle)
Arguments
angle |
numerical value giving an angle in degrees |
Value
angle2hms returns a list containing
values time (a numerical value for decimal hour, between 0 and 24),
hour, minute, and second (the last of which may have a fractional
part), and string, a character value indicates the time in hour-minute-second
notation, with the second part to two decimal places and intervening h,
m and s characters between the units.
Author(s)
Dan Kelley
References
Meeus, Jean. Astronomical Algorithms. Second Edition. Richmond, Virginia, USA: Willmann-Bell, 1991.
See Also
Other things related to astronomy:
eclipticalToEquatorial(),
equatorialToLocalHorizontal(),
julianCenturyAnomaly(),
julianDay(),
moonAngle(),
siderealTime(),
sunAngle(),
sunDeclinationRightAscension()
Examples
# A randomly-chosen example on page 99 of Meeus (1991).
angle2hms(177.74208) # string component 11h50m58s.10