format_period_multi: Create consistent, complete multi-year periods

In johnrbryant/demprep: Prepare Demographic Data

Description

Given a vector of period labels, create a factor containing levels for the earliest and latest periods in x, and for all periods in between. All periods have the same width, which is controlled by the width argument.

Usage

format_period_multi(
  x,
  width = 5,
  origin = 2000,
  month_start = "Jan",
  label_year_start = TRUE
)

Arguments

x	A vector of period labels.
width	The width, in whole years, of the periods to be created. Defaults to 5.
origin	An integer. Defaults to 2000.
month_start	An element of month.name, or month.abb. Periods start on the first day of this month.
label_year_start	Logical. Whether to label a period by the calendar year at the beginning of the period or the calendar year at the end. Defaults to TRUE.

Details

The elements of x are typically multi-year labels such as "1950-1960" or "2020-2025" or single-year labels such as "2000" or "2025". x cannot contain open intervals such as "<2020".

As discussed in date_to_period_year, single-year labels such as "2000" are ambiguous. Correctly aligning single-year and multi-year periods requires knowing which month the single-year periods start on, which is controlled by the month_start argument, and whether single-year periods are labelled according to the calendar year at the start or end of the period, which is controlled by the label_year_start argument.

The location of the periods can be shifted by using different values for origin.

If x contains NA, then the levels of the factor created by format_period_multi also contain NA.

Value

A factor with the same length as x.

See Also

Other functions for reformating period labels are

• format_period_year

• format_period_custom

• format_period_quarter

• format_period_month

date_to_period_year creates periods from dates.

Examples

format_period_multi(x = c("2000-2001", "2005-2010", NA, "1996-1998"))

## use non-default value for 'width'
format_period_multi(x = c("2000-2001", "2005-2010", NA, "1996-1998"),
                    width = 10)

## use non-default value for 'origin' to shift periods
format_period_multi(x = c("2000-2001", "2005-2010", NA, "1996-1998"),
                    width = 10,
                    origin = 2001)

## Labels include single-year periods. Use default assumption
## that single-year periods start in January and/or
## are labelled by the calendar year at the start of
## the period
format_period_multi(x = c("2000-2001", "2005", NA, "1996-1998"))

## Change to assumption that single-year periods are
## start in July, and are labelled by the calendar
## year at the end of the period
format_period_multi(x = c("2000-2001", "2005", NA, "1996-1998"),
                    month_start = "Jul",
                    label_year_start = FALSE)

johnrbryant/demprep documentation built on Dec. 31, 2021, 11:58 a.m.