time.to.tick: Convert date to tick number

In jacobnabe/DEPONS2R: Read, Plot and Analyse Output from the DEPONS Model

Convert date to tick number

Description

Convert a date to the number of ticks since simulation start while taking into account that DEPONS assumes that there are 360 days in a simulation year.

Usage

time.to.tick(time, timestep = 30, origin = "2010-01-01", tz = "UTC", ...)

Arguments

time	Character, or character vector, of the form 'YYYY-MM-DD' (or 'YYYY-MM-DD HH:MM:SS'), or equivalent POSIX object. Date to be converted to ticks.
timestep	Numeric (default 30). Length of each simulation time step in minutes.
origin	Character of the form 'YYYY-MM-DD' (or 'YYYY-MM-DD HH:MM:SS') or equivalent POSIX object (default "2010-01-01"). Start date of simulation.
tz	Valid time zone code (default UTC).
...	Optional parameters.

Details

Times are rounded down to the current 30-minute interval during conversion. The function assumes that there are 30 days in each month, except in January, February and March with 31, 28 and 31 days, respectively. Provided dates that fall on days that are not accommodated (February 29, and the 31st day of the months May, July, August, October, and December) are returned as NA.

The function may be used to, e.g., convert recorded piling dates to ticks for use in wind farm scenarios (see make.windfarms for construction of hypothetical scenarios from parametric inputs).

Value

Numeric vector of tick numbers.

See Also

tick.to.time is the inverse of this function, converting ticks to dates

Examples

## Not run: 
#Uses date column of AIS data.
#Times are in 30-minute intervals, and converting back yields the same times
data(aisdata)
ticks <- time.to.tick(aisdata$time, origin = "2015-12-20")
times_reconverted <- tick.to.time(ticks, origin = "2015-12-20")

#Uses dates at other intervals.
#Converting back yields times rounded down to the current 30-minute interval
times <- c("2016-12-20 00:10:00",
          "2016-12-20 02:45:30",
          "2016-12-20 05:01:05",
          "2016-12-22 01:30:00")
ticks <- time.to.tick(times, origin = "2015-12-20")
times_reconverted <- tick.to.time(ticks, origin = "2015-12-20")
## End(Not run)

jacobnabe/DEPONS2R documentation built on Dec. 11, 2024, 2:05 a.m.