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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/sampling.R
\name{downSample}
\alias{downSample}
\alias{upSample}
\title{Down- and Up-Sampling Imbalanced Data}
\usage{
downSample(x, y, list = FALSE, yname = "Class")
}
\arguments{
\item{x}{a matrix or data frame of predictor variables}
\item{y}{a factor variable with the class memberships}
\item{list}{should the function return \code{list(x, y)} or bind \code{x}
and \code{y} together? If \code{FALSE}, the output will be coerced to a data
frame.}
\item{yname}{if \code{list = FALSE}, a label for the class column}
}
\value{
Either a data frame or a list with elements \code{x} and \code{y}.
}
\description{
\code{downSample} will randomly sample a data set so that all classes have
the same frequency as the minority class. \code{upSample} samples with
replacement to make the class distributions equal
}
\details{
Simple random sampling is used to down-sample for the majority class(es).
Note that the minority class data are left intact and that the samples will
be re-ordered in the down-sampled version.
For up-sampling, all the original data are left intact and additional
samples are added to the minority classes with replacement.
}
\examples{
## A ridiculous example...
data(oil)
table(oilType)
downSample(fattyAcids, oilType)
upSample(fattyAcids, oilType)
}
\author{
Max Kuhn
}
\keyword{utilities}
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