expand {messydates}

Expand messy dates to lists of dates

Description

These functions expand on date ranges, sets of dates, and unspecified or approximate dates (annotated with '..', '', 'XX' or '~'). As these messydates may refer to several possible dates, the function "opens" these values to reveal a vector of all the possible dates implied. Imprecise dates (dates only containing information on year and/or month) are also expanded to include possible dates within that year and/or month. The function removes the annotation from dates with unreliable sources ('?'), before being expanded normally as though they were incomplete.

Usage

expand(x, approx_range = 0)

Arguments

x

A mdate object. If not an 'mdate' object, conversion is handled first with ´as_messydate()´.

approx_range

Range to expand approximate dates, or date components, annotated with '~', by default 0. That is, removes signs for approximate dates and treats these dates as precise dates. If 3, for example, adds 3 days for day approximation, 3 months for month approximation, 3 years for year/whole date approximation, 3 years and 3 months for year-month approximation, and 3 months and 3 days for month-day approximation.

Value

A list of dates, including all dates in each range or set.

Examples

d <- as_messydate(c("2008-03-25", "-2012-02-27", "2001-01?", "~2001",
"2001-01-01..2001-02-02", "{2001-01-01,2001-02-02}", "{2001-01,2001-02-02}",
"2008-XX-31", "..2002-02-03", "2001-01-03..", "28 BC"))
expand(d)