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Logical statements on messy dates

Source: R/operate_statements.R
operate_statements.Rd

These functions provide various logical statements about messy date objects.

Usage

is_messydate(x)

is_intersecting(x, y)

is_subset(x, y)

is_similar(x, y)

is_precise(x)

is_uncertain(x)

is_approximate(x)

is_bce(x)

Arguments

x, y

mdate or other class objects

Value

A logical vector the same length as the mdate passed.

Functions

  • is_messydate(): tests whether the object inherits the mdate class. If more rigorous validation is required, see validate_messydate().

  • is_intersecting(): tests whether there is any intersection between two messy dates, leveraging intersect().

  • is_subset(): tests whether one or more messy date can be found within a messy date range or set.

  • is_similar(): tests whether two dates contain similar components. This can be useful for identifying dates that may be typos of one another.

  • is_precise(): tests whether a date (or date-time) is precise, i.e. a full "yyyy-mm-dd", optionally with a time of day (down to the hour, minute, or second) and time zone. Non-precise dates contain markers that they are approximate (i.e. ~), unreliable (i.e. ?), are incomplete (e.g. year or year-month only, or a date with an unspecified X component), or are date ranges and sets.

  • is_uncertain(): tests whether a date is uncertain (i.e. contains ?).

  • is_approximate(): tests whether a date is approximate (i.e. contains ~).

  • is_bce(): tests whether one or more messy dates are found before the common era, i.e. carry a negative (astronomical) year. Note that astronomical year zero ("0000", historically 1 BCE) is not sign-negative and so returns FALSE; it is handled natively as a non-negative year throughout, which R's proleptic Gregorian Date supports directly.

Examples

is_messydate(as_messydate("2012-01-01"))
#> [1] TRUE
is_messydate(as.Date("2012-01-01"))
#> [1] FALSE
is_intersecting(as_messydate("2012-01"),
as_messydate("2012-01-01..2012-02-22"))
#> [1] TRUE
is_intersecting(as_messydate("2012-01"),
as_messydate("2012-02-01..2012-02-22"))
#> [1] FALSE
is_subset(as_messydate("2012-01-01"), as_messydate("2012-01"))
#> [1] TRUE
is_subset(as_messydate("2012-01-01..2012-01-03"), as_messydate("2012-01"))
#> [1] TRUE
is_subset(as_messydate("2012-01-01"), as_messydate("2012-02"))
#> [1] FALSE
is_similar(as_messydate("2012-06-02"), as_messydate("2012-02-06"))
#> [1] TRUE
is_similar(as_messydate("2012-06-22"), as_messydate("2012-02-06"))
#> [1] FALSE
is_precise(as_messydate(c("2012-06-02", "2012-06")))
#> [1]  TRUE FALSE
is_precise(as_messydate(c("2012-06-02 14:30:00", "2012-06-02 ~14")))
#> [1]  TRUE FALSE
is_uncertain(as_messydate(c("2012-06-02", "2012-06-02?")))
#> [1] FALSE  TRUE
is_approximate(as_messydate(c("2012-06-02~", "2012-06-02")))
#> [1]  TRUE FALSE
is_bce(as_messydate(c("2012-06-02", "-2012-06-02")))
#> [1] FALSE  TRUE