This function calculates the last frost day from a numeric vector of daily minimum temperatures using tidyverse principles.
Usage
last_frost_day(
.data,
threshold = get_weather_option("extreme.frost_threshold"),
hemisphere = "south",
require_full_year = get_weather_option("require_full_year")
)Arguments
- .data
A data frame or tibble containing daily minimum temperatures in a column named "mint".
- threshold
The stress temperature threshold for frost (default: 0)
- hemisphere
Hemisphere indicator: "south" or "north" (default: "south"). If latitude information is available in the data, it will be used to determine the hemisphere.
- require_full_year
Logical. If TRUE, requires exactly 365 or 366 days (default: TRUE)
Value
An data.frame or tibble representing the day of year for the last frost, or NA if no frost occurs
Examples
file <- system.file("extdata/ppd_72150.met", package = "tidyweather")
records <- read_weather(file)
records |>
dplyr::group_by(year) |>
last_frost_day(require_full_year = FALSE)
#> # A tibble: 3 × 2
#> # Groups: year [3]
#> year last_frost_day
#> <dbl> <dbl>
#> 1 2023 NA
#> 2 2024 262
#> 3 2025 183