compute_duration: Compute Duration

In admiral: ADaM in R Asset Library

Compute Duration

Description

Compute duration between two dates, e.g., duration of an adverse event, relative day, age, ...

Usage

compute_duration(
  start_date,
  end_date,
  in_unit = "days",
  out_unit = "days",
  floor_in = TRUE,
  add_one = TRUE,
  trunc_out = FALSE,
  type = "duration"
)

Arguments

start_date	The start date A date or date-time object is expected. Refer to derive_vars_dt() to impute and derive a date from a date character vector to a date object. Refer to convert_dtc_to_dt() to obtain a vector of imputed dates.
end_date	The end date A date or date-time object is expected. Refer to derive_vars_dt() to impute and derive a date from a date character vector to a date object. Refer to convert_dtc_to_dt() to obtain a vector of imputed dates.
in_unit	Input unit See floor_in and add_one parameter for details. Permitted Values (case-insensitive): For years: "year", "years", "yr", "yrs", "y" For months: "month", "months", "mo", "mos" For days: "day", "days", "d" For hours: "hour", "hours", "hr", "hrs", "h" For minutes: "minute", "minutes", "min", "mins" For seconds: "second", "seconds", "sec", "secs", "s"
out_unit	Output unit The duration is derived in the specified unit Permitted Values (case-insensitive): For years: "year", "years", "yr", "yrs", "y" For months: "month", "months", "mo", "mos" For weeks: "week", "weeks", "wk", "wks", "w" For days: "day", "days", "d" For hours: "hour", "hours", "hr", "hrs", "h" For minutes: "minute", "minutes", "min", "mins" For seconds: "second", "seconds", "sec", "secs", "s"
floor_in	Round down input dates? The input dates are round down with respect to the input unit, e.g., if the input unit is 'days', the time of the input dates is ignored. Default: TRUE Permitted Values: TRUE, FALSE
add_one	Add one input unit? If the duration is non-negative, one input unit is added. i.e., the duration can not be zero. Default: TRUE Permitted Values: TRUE, FALSE
trunc_out	Return integer part The fractional part of the duration (in output unit) is removed, i.e., the integer part is returned. Default: FALSE Permitted Values: TRUE, FALSE
type	lubridate duration type. See below for details. Default: "duration" Permitted Values: "duration", "interval"

Details

The output is a numeric vector providing the duration as time from start to end date in the specified unit. If the end date is before the start date, the duration is negative.

Value

The duration between the two date in the specified unit

Duration Type

The lubridate package calculates two types of spans between two dates: duration and interval. While these calculations are largely the same, when the unit of the time period is month or year the result can be slightly different.

The difference arises from the ambiguity in the length of "1 month" or "1 year". Months may have 31, 30, 28, or 29 days, and years are 365 days and 366 during leap years. Durations and intervals help solve the ambiguity in these measures.

The interval between 2000-02-01 and 2000-03-01 is 1 (i.e. one month). The duration between these two dates is 0.95, which accounts for the fact that the year 2000 is a leap year, February has 29 days, and the average month length is 30.4375, i.e. 29 / 30.4375 = 0.95.

For additional details, review the lubridate time span reference page.

See Also

derive_vars_duration()

Date/Time Computation Functions that returns a vector: compute_age_years(), compute_dtf(), compute_tmf(), convert_date_to_dtm(), convert_dtc_to_dt(), convert_dtc_to_dtm(), impute_dtc_dt(), impute_dtc_dtm()

Examples

library(lubridate)

# Derive duration in days (integer), i.e., relative day
compute_duration(
  start_date = ymd_hms("2020-12-06T15:00:00"),
  end_date = ymd_hms("2020-12-24T08:15:00")
)

# Derive duration in days (float)
compute_duration(
  start_date = ymd_hms("2020-12-06T15:00:00"),
  end_date = ymd_hms("2020-12-24T08:15:00"),
  floor_in = FALSE,
  add_one = FALSE
)

# Derive age in years
compute_duration(
  start_date = ymd("1984-09-06"),
  end_date = ymd("2020-02-24"),
  trunc_out = TRUE,
  out_unit = "years",
  add_one = FALSE
)

# Derive duration in hours
compute_duration(
  start_date = ymd_hms("2020-12-06T9:00:00"),
  end_date = ymd_hms("2020-12-06T13:30:00"),
  out_unit = "hours",
  floor_in = FALSE,
  add_one = FALSE,
)

admiral documentation built on June 22, 2024, 9:06 a.m.