date_extremes: Latest and Earliest Dates

In TalhoukLab/biostatUtil: Utility Functions Used in Biostatistics Projects

Latest and Earliest Dates

Description

Finds the latest (max) and earliest (min) date given a vector of dates. The functions ending in Array find the extremes for an array of dates as opposed to a vector.

Usage

maxDate(dates, na.rm = TRUE)

minDate(dates, na.rm = TRUE)

maxDateArray(
  t.arr,
  date.format = "MM.DD.YYYY",
  existing.missing.codes = NA,
  return.missing.code = NA,
  sep = "/"
)

minDateArray(
  t.arr,
  date.format = "MM.DD.YYYY",
  existing.missing.codes = NA,
  return.missing.code = NA,
  sep = "/"
)

Arguments

dates	vector of dates
na.rm	logical. Should NAs be removed?
t.arr	array of date strings
date.format	format of the array of dates
existing.missing.codes	missing dates
return.missing.code	what to return if there is a missing input
sep	date separator. Defaults to "/"

Details

The input vector should have dates formatted as YYYY-MM-DD. If na.rm is not set to the default (TRUE) and dates has NA values, then the function will also return NA.

Value

The latest or earliest date from a vector of dates.

Author(s)

Samuel Leung, Derek Chiu

Examples

## No NA
t1 <- as.Date(c("2015-03-01", "2015-02-15", "2015-05-01"))
minDate(t1)
maxDate(t1)

## With NA
t2 <- as.Date(c("2015-03-01", "2015-02-15", NA, "2014-05-01"))
maxDate(t2)
minDate(t2)
minDate(t2, na.rm = FALSE)

## Array of dates
many.dates <- c("03/21/1992", "04/21/2013", "10/10/2015")
maxDateArray(many.dates)
minDateArray(many.dates)

many.dates <- c("2009-03-01", "2010-01-12", "2015-01-11")
maxDateArray(many.dates, sep = "-")
minDateArray(many.dates, sep = "-")

ties.dates <- c("2009-03-01", "2010-01-12", "2010-01-12")
maxDateArray(ties.dates, sep = "-")
minDateArray(ties.dates, sep = "-")

TalhoukLab/biostatUtil documentation built on April 14, 2025, 4:15 a.m.