File: performance-class.Rd

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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/zzz.R
\docType{class}
\name{performance-class}
\alias{performance-class}
\title{Class \code{performance}}
\description{
Object to capture the result of a performance evaluation, optionally
collecting evaluations from several cross-validation or bootstrapping runs.
}
\details{
A \code{performance} object can capture information from four
different evaluation scenarios:
  \itemize{
    \item The behaviour of a cutoff-dependent performance measure across
    the range of all cutoffs (e.g. \code{performance( predObj, 'acc' )} ). Here,
    \code{x.values} contains the cutoffs, \code{y.values} the
    corresponding values of the performance measure, and
    \code{alpha.values} is empty.\cr
    \item The trade-off between two performance measures across the
    range of all cutoffs (e.g. \code{performance( predObj,
                                                  'tpr', 'fpr' )} ). In this case, the cutoffs are stored in
    \code{alpha.values}, while \code{x.values} and \code{y.values}
    contain the corresponding values of the two performance measures.\cr
    \item A performance measure that comes along with an obligatory
    second axis (e.g. \code{performance( predObj, 'ecost' )} ). Here, the measure values are
    stored in \code{y.values}, while the corresponding values of the
    obligatory axis are stored in \code{x.values}, and \code{alpha.values}
    is empty.\cr
    \item A performance measure whose value is just a scalar
    (e.g. \code{performance( predObj, 'auc' )} ). The value is then stored in
    \code{y.values}, while \code{x.values} and \code{alpha.values} are
    empty.
  }
}
\section{Slots}{

\describe{
\item{\code{x.name}}{Performance measure used for the x axis.}

\item{\code{y.name}}{Performance measure used for the y axis.}

\item{\code{alpha.name}}{Name of the unit that is used to create the parametrized
curve. Currently, curves can only be parametrized by cutoff, so
\code{alpha.name} is either \code{none} or \code{cutoff}.}

\item{\code{x.values}}{A list in which each entry contains the x values of the curve
of this particular cross-validation run. \code{x.values[[i]]},
\code{y.values[[i]]}, and \code{alpha.values[[i]]} correspond to each
other.}

\item{\code{y.values}}{A list in which each entry contains the y values of the curve
of this particular cross-validation run.}

\item{\code{alpha.values}}{A list in which each entry contains the cutoff values of
the curve of this particular cross-validation run.}
}}

\section{Objects from the Class}{

Objects can be created by using the \code{performance} function.
}

\references{
A detailed list of references can be found on the ROCR homepage at
\url{http://rocr.bioinf.mpi-sb.mpg.de}.
}
\seealso{
\code{\link{prediction}}
\code{\link{performance}},
\code{\link{prediction-class}},
\code{\link{plot.performance}}
}
\author{
Tobias Sing \email{tobias.sing@gmail.com}, Oliver Sander
\email{osander@gmail.com}
}