Calculate Date of Accumulated Thermal Units (ATUs)

Calculates the date on which a specified number of Accumulated Thermal Units (ATUs) are meet or exceeded.

Usage

date_atus(x, atus = 600, start_date = as.Date("1972-03-01"))

Arguments

x

A data frame with two columns date and temperature. date, which must be of class Date provides the dates and temperature which must be a numeric vector provides the mean daily water temperature in degrees centigrade.

atus

A positive number of the accumulated thermal units to exceed.

start_date

A Date scalar of the first date within each year to consider (the year is ignored). #' If start_date occurs before the end_date (when ignoring the year) then the window is considered to span two calendar years.

Value

A tibble with four columns year, start_date, end_date and atus.

Examples

date_atus(gsdd::temperature_data)
#> # A tibble: 2 × 4
#> # Groups:   year [2]
#>    year start_date end_date    atus
#>   <int> <date>     <date>     <dbl>
#> 1  2018 1971-03-01 NA           NA 
#> 2  2019 1971-03-01 1971-05-11  617.