| Title: | Datetimes as Integers for Discrete-Event Simulations |
|---|---|
| Description: | Handles datetimes as integers for the usage inside Discrete-Event Simulations (DES). The conversion is made using the internally generic function as.numeric() of the base package. DES is described in Simulation Modeling and Analysis by Averill Law and David Kelton (1999) <doi:10.2307/2288169>. |
| Authors: | Adrian Staempfli, Christoph Strauss, Michael Schmid |
| Maintainer: | Adrian Staempfli <[email protected]> |
| License: | GPL-3 |
| Version: | 4.0.0 |
| Built: | 2024-11-12 05:56:43 UTC |
| Source: | https://github.com/ims-fhs/simtimer |
as.datetime() transforms a sim_datetime element (integer) to a regular datetime element (POSIXt)
as.datetime(sim_datetime, origin_date)as.datetime(sim_datetime, origin_date)
sim_datetime |
A sim_datetime (integer representing the passed seconds since origin_date) |
origin_date |
A datetime (POSIXt) |
datetime A POSIXt
origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") as.datetime(60, origin_date) # [1] "2016-01-01 00:01:00 UTC" as.datetime(600, origin_date) # [1] "2016-01-01 00:10:00 UTC" as.datetime(as.sim_datetime(as.POSIXct("2016-01-02 00:00:00", tz = "UTC"), origin_date), origin_date) # [1] "2016-01-02 UTC"origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") as.datetime(60, origin_date) # [1] "2016-01-01 00:01:00 UTC" as.datetime(600, origin_date) # [1] "2016-01-01 00:10:00 UTC" as.datetime(as.sim_datetime(as.POSIXct("2016-01-02 00:00:00", tz = "UTC"), origin_date), origin_date) # [1] "2016-01-02 UTC"
as.sim_datetime() transforms a regular datetime element (POSIXt) to a sim_datetime (integer representing the passed seconds since origin_date). The timezone (tz) will be ignored at the moment. Therefore tz of datetime and origin_date should be identical.
as.sim_datetime(datetime, origin_date)as.sim_datetime(datetime, origin_date)
datetime |
A datetime (POSIXt) |
origin_date |
A datetime (POSIXt) |
A sim_datetime
origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") as.sim_datetime(as.POSIXct("2016-01-01 00:01:00", tz = "UTC"), origin_date) # [1] 60 as.sim_datetime(as.POSIXct("2016-01-02 00:01:00", tz = "UTC"), origin_date) # [1] 86460origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") as.sim_datetime(as.POSIXct("2016-01-01 00:01:00", tz = "UTC"), origin_date) # [1] 60 as.sim_datetime(as.POSIXct("2016-01-02 00:01:00", tz = "UTC"), origin_date) # [1] 86460
sim_date() returns the date part of a sim_datetime. Therefore sim_date() calculates the number of days (24h-intervals) that have passed since origin_date. If the origin_date of sim_datetime has a time component different than 00:00:00, the 24h-intervals are correlated to this particular time component.
sim_date(sim_datetime)sim_date(sim_datetime)
sim_datetime |
A sim_datetime (integer representing the passed seconds since origin_date) |
the number of days (24h-intervals) that have passed since origin_date
sim_date(24*60*60-1) # [1] 0 sim_date(24*60*60) # [1] 1 sim_date(452*24*60*60) # [1] 452 origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") sim_date(as.sim_datetime(as.POSIXct("2016-01-02 00:01:00", tz = "UTC"), origin_date)) # [1] 1sim_date(24*60*60-1) # [1] 0 sim_date(24*60*60) # [1] 1 sim_date(452*24*60*60) # [1] 452 origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") sim_date(as.sim_datetime(as.POSIXct("2016-01-02 00:01:00", tz = "UTC"), origin_date)) # [1] 1
sim_time() returns the time of a sim_datetime in seconds. The beginning of a day is defined by the time component of origin_date which defines the parameter sim_datetime.
sim_time(sim_datetime)sim_time(sim_datetime)
sim_datetime |
A sim_datetime (integer representing the passed seconds since origin_date) |
time in seconds (Range: 0-(24*60*60-1))
sim_time(200) # [1] 200 sim_time(24*60*60-1) # [1] 86399 sim_time(24*60*60) # [1] 0 origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") sim_time(as.sim_datetime(as.POSIXct("2016-01-01 00:01:00", tz = "UTC"), origin_date)) # [1] 60 sim_time(as.sim_datetime(as.POSIXct("2016-01-02 00:01:00", tz = "UTC"), origin_date)) # [1] 60sim_time(200) # [1] 200 sim_time(24*60*60-1) # [1] 86399 sim_time(24*60*60) # [1] 0 origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") sim_time(as.sim_datetime(as.POSIXct("2016-01-01 00:01:00", tz = "UTC"), origin_date)) # [1] 60 sim_time(as.sim_datetime(as.POSIXct("2016-01-02 00:01:00", tz = "UTC"), origin_date)) # [1] 60
sim_wday() returns the weekday of a sim_datetime. It's crucial to use the same origin_date for sim_wday() than the origin_date that was used to generate the sim_datetime. sim_wday() uses the base R format(x, "%u") function.
sim_wday(sim_datetime, origin_date)sim_wday(sim_datetime, origin_date)
sim_datetime |
A sim_datetime (integer representing the passed seconds since origin_date) |
origin_date |
A datetime (POSIXt) |
A character, giving the weekday number ("1" = Monday, "2" = Tuesday, ..., "7" = Sunday)
origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") sim_wday(60, origin_date) sim_wday(3600,origin_date) sim_wday(36*3600,origin_date)origin_date <- as.POSIXct("2016-01-01 00:00:00", tz = "UTC") sim_wday(60, origin_date) sim_wday(3600,origin_date) sim_wday(36*3600,origin_date)