\name{k3.linear}
\alias{k3.linear}
\title{
Linear Skewness Estimate
}
\description{
Estimates the skewness of a statistic from its empirical influence values.
}
\usage{
k3.linear(L, strata = NULL)
}
\arguments{
\item{L}{
Vector of the empirical influence values of a statistic.  These will usually
be calculated by a call to \code{empinf}.
}
\item{strata}{
A numeric vector or factor specifying which observations (and hence which
components of \code{L}) come from which strata.
}}
\value{
The skewness estimate calculated from \code{L}.
}
\references{
Davison, A. C. and Hinkley, D. V. (1997) 
\emph{Bootstrap Methods and Their Application}. Cambridge University Press.
}
\seealso{
\code{\link{empinf}}, \code{\link{linear.approx}}, \code{\link{var.linear}}
}
\examples{
#  To estimate the skewness of the ratio of means for the city data.
ratio <- function(d, w) sum(d$x * w)/sum(d$u * w)
k3.linear(empinf(data = city, statistic = ratio))
}
\keyword{nonparametric}
% Converted by Sd2Rd version 1.15.