Add / Subtract (For Time Series)
The easiest way to add / subtract a period to a time series date or date-time vector.
add_time(index, period) subtract_time(index, period) index %+time% period index %-time% period
index |
A date or date-time vector. Can also accept a character representation. |
period |
A period to add. Accepts character strings like "5 seconds", "2 days", and complex strings like "1 month 4 days 34 minutes". |
A convenient wrapper for lubridate::period(). Adds and subtracts a period from a
time-based index. Great for:
Finding a timestamp n-periods into the future or past
Shifting a time-based index. Note that NA values may be present where dates don't exist.
Period Specification
The period argument accepts complex strings like:
"1 month 4 days 43 minutes"
"second = 3, minute = 1, hour = 2, day = 13, week = 1"
A date or datetime (POSIXct) vector the same length as index with the
time values shifted +/- a period.
Other Time-Based vector functions:
between_time() - Range detection for date or date-time sequences.
Underlying function:
library(timetk)
# ---- LOCATING A DATE N-PERIODS IN FUTURE / PAST ----
# Forward (Plus Time)
"2021" %+time% "1 hour 34 seconds"
"2021" %+time% "3 months"
"2021" %+time% "1 year 3 months 6 days"
# Backward (Minus Time)
"2021" %-time% "1 hour 34 seconds"
"2021" %-time% "3 months"
"2021" %-time% "1 year 3 months 6 days"
# ---- INDEX SHIFTING ----
index_daily <- tk_make_timeseries("2016", "2016-02-01")
# ADD TIME
# - Note `NA` values created where a daily dates aren't possible
# (e.g. Feb 29 & 30, 2016 doesn't exist).
index_daily %+time% "1 month"
# Subtracting Time
index_daily %-time% "1 month"Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.