% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/agroclimatic.R
\name{ck_winkler}
\alias{ck_winkler}
\title{Winkler Index}
\usage{
ck_winkler(tavg, dates)
}
\arguments{
\item{tavg}{Numeric vector of daily average temperatures (degrees C).}

\item{dates}{Date vector of the same length as \code{tavg}.}
}
\value{
A data frame with columns \code{period}, \code{value}, \code{index}, and \code{unit}.
}
\description{
The Winkler index (also called growing degree days for viticulture)
accumulates daily mean temperature above 10 degrees C during the growing season
(April-October in NH, October-April in SH).
}
\examples{
dates <- seq(as.Date("2024-04-01"), as.Date("2024-10-31"), by = "day")
set.seed(42)
tavg <- rnorm(length(dates), mean = 18, sd = 4)
ck_winkler(tavg, dates)
}
\references{
Amerine, M. A., & Winkler, A. J. (1944). Composition and
quality of musts and wines of California grapes.
}
