epi_calendar: Determine Epidemiological Season

epi_calendarR Documentation

Determine Epidemiological Season

Description

This function identifies the epidemiological season, (must span new year) to which a given date belongs. The epidemiological season is defined by a start and end week, where weeks are numbered according to the ISO week date system.

Usage

epi_calendar(date, start = 21, end = 20)

Arguments

date

A date object representing the date to check.

start

An integer specifying the start week of the epidemiological season.

end

An integer specifying the end week of the epidemiological season.

Value

A character vector indicating the season:

  • "out_of_season" if the date is outside the specified season,

  • If within the season, the function returns a character string indicating the epidemiological season.

Examples

# Check if a date is within the epidemiological season
epi_calendar(as.Date("2023-09-15"), start = 21, end = 20)
# Expected output: "2023/2024"

epi_calendar(as.Date("2023-05-30"), start = 40, end = 20)
# Expected output: "out_of_season"

try(epi_calendar(as.Date("2023-01-15"), start = 1, end = 40))
# Expected error: "`start` must be greater than `end`!"

epi_calendar(as.Date("2023-10-06"), start = 40, end = 11)
# Expected output: "2023/2024"

aedseo documentation built on April 12, 2025, 1:35 a.m.