period_class: Period class

In grates: Grouped Date Classes

Period class

Description

⁠<grates_period>⁠ objects represent groupings of n consecutive days calculated relative to an offset. It is useful for when you wish to group an arbitrary number of dates together (e.g. 10 days).

Usage

as_period(x, n, ...)

## Default S3 method:
as_period(x, n = 1L, offset = 0L, ...)

## S3 method for class 'Date'
as_period(x, n = 1L, offset = 0L, ...)

## S3 method for class 'POSIXt'
as_period(x, n = 1L, offset = 0L, ...)

## S3 method for class 'character'
as_period(x, n = 1L, offset = 0L, ...)

## S3 method for class 'factor'
as_period(x, n = 1L, offset = 0L, ...)

new_period(x = integer(), n = 1L, offset = 0L)

is_period(xx)

Arguments

x, xx	R objects. For as_period() this is the object to be coerced. For new_period() this represents the number of periods since the Unix Epoch (1970-01-01) and a specified offset.
n	⁠[integer]⁠ Number of days that are being grouped.
...	Only used for character input where additional arguments are passed through to as.Date().
offset	⁠[integer]⁠ or, for as_period(), a ⁠[date]⁠. Value you wish to start counting periods from relative to the Unix Epoch: For integer values this is stored scaled by n (offset <- as.integer(offset) %% n). For date values this is first converted to an integer offset (offset <- floor(as.numeric(offset))) and then scaled via n as above.

Details

Internally grates_period objects are stored as the integer number, starting at 0, of periods since the Unix Epoch (1970-01-01) and a specified offset. Here periods are taken to mean groupings of n consecutive days. For storage and calculation purposes, offset is scaled relative to n (i.e. offset <- offset %% n) and values of x stored relative to this scaled offset.

as_period() is a generic for coercing input in to ⁠<grates_period>⁠ objects. It is the recommended way for constructing period objects as it allows the offset to be specified as a date (rather than an integer value relative to the Unix Epoch).

• Character input is first parsed using as.Date().

• POSIXct and POSIXlt are converted with their timezone respected.

new_period() is a minimal constructor for ⁠<grates_period>⁠ objects aimed at developers. It takes, as input, the number of periods since the Unix Epoch and the specified offset. double vectors will be converted via as.integer(floor(x)).

Value

A ⁠<grates_period>⁠ object.

Examples

# coercion from date
dat <- as.Date("2012-12-01")
as_period(dat + 0:3, n = 2, offset = dat)

# direct construction
new_period(1:10)

grates documentation built on April 3, 2025, 10:49 p.m.