Extracting components from messy dates

These functions allow the extraction of particular date components from messy dates, such as the year(), month(), and day(). precision() allows for the identification of the greatest level of precision in (currently) the first element of each date.

Usage

year(x)

month(x)

day(x)

precision(x)

# S3 method for class 'mdate'
precision(x)

Arguments

x

A mdate object

Value

year(), month(), and day() extraction return the integer for the requested date component. precision() returns the level of greatest precision for each date.

Precision

Date precision is measured relative to the day in \(1/days(x)\). That is, a date measured to the day will return a precision score of 1, a date measured to the month will return a precision score of between \(1/28\) and \(1/31\), and annual measures will have a precision of between \(1/365\) and \(1/366\).

Examples

year(as_messydate(c("2012-02-03","2012","2012-02")))
#> [1] 2012 2012 2012
month(as_messydate(c("2012-02-03","2012","2012-02")))
#> [1]  2 NA  2
day(as_messydate(c("2012-02-03","2012","2012-02")))
#> [1]  3 NA NA
precision(as_messydate(c("2012-02-03","2012","2012-02")))
#> [1] 1.00000000 0.00273224 0.03448276