gmt {moonsun} | R Documentation |
The functions for creating a time (or time sequences) measured in Greenwich Mean Time (gmt), Greenwich Sidereal Time (gst), Local Sidereal Time (lst), Local Time (lt).
gmt(hour = NULL, minute = 0, second = 0, epoch = Sys.time(), length = 1, by = 1) gst(jday = jd(), hour = NULL, minute = 0, second = 0, epoch = Sys.time(), length = 1, by = 1) lst(..., lambda = getOption("longitude")) lt(hour = NULL, minute = 0, second = 0, epoch = Sys.time(), length = 1, by = 1)
jday |
Julian Day Number |
hour |
hour |
minute |
minute |
second |
second |
epoch |
epoch |
length |
length |
by |
step in sequence |
... |
additional arguments |
lambda |
longitude of the observer, default taken from options |
The functions gmt() and lt() are simple time series generators. By default they take current time expressed as local or GMT.
The functions lst() and gst() compute sidereal times for given Julian Day Number and time. Default is for now.
A vector containing times expressed as hours from 00h 00m 00s, of class "time".
Lukasz Komsta
lt() gmt() gst() lst() options(latitude=51,longitude=22) lst(jd(2008,01,01),hour=12) # Local Sidereal Time, 1st January 2008 1200 UTC lst(length=10) # 10 hours ahead sequence from now