gmt: Create sequences of a time In moonsun: Basic astronomical calculations with R

Description

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).

Usage

 ```1 2 3 4 5``` ```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) ```

Arguments

 `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

Details

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.

Value

A vector containing times expressed as hours from 00h 00m 00s, of class "time".

Lukasz Komsta

Examples

 ```1 2 3 4 5 6 7``` ```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 ```

moonsun documentation built on May 29, 2017, 12:17 p.m.