\HeaderA{multiecdf}{Multiple empirical cumulative distribution functions (ecdf)
and densities}{multiecdf}
\aliasA{multidensity}{multiecdf}{multidensity}
\methaliasA{multidensity.default}{multiecdf}{multidensity.default}
\methaliasA{multidensity.formula}{multiecdf}{multidensity.formula}
\methaliasA{multiecdf.default}{multiecdf}{multiecdf.default}
\methaliasA{multiecdf.formula}{multiecdf}{multiecdf.formula}
\keyword{hplot}{multiecdf}
\begin{Description}\relax
Plot multiple empirical cumulative distribution functions (ecdf)
and densities with user interface similar to that of \code{\LinkA{boxplot}{boxplot}}.
\end{Description}
\begin{Usage}
\begin{verbatim}
multiecdf(x, ...)
## S3 method for class 'formula':
multiecdf(formula, data = NULL, ..., na.action = NULL)
## Default S3 method:
multiecdf(x, xlim, col, do.points=FALSE, subsample=TRUE, ...)

multidensity(x, ...)
## S3 method for class 'formula':
multidensity(formula, data = NULL, main, xlab, ..., na.action = NULL)
## Default S3 method:
multidensity(x, bw="nrd0", xlim, ylim, col, main, xlab, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{formula}] a formula, such as \code{y \textasciitilde{} grp}, where \code{y} is a
numeric vector of data values to be split into groups according to
the grouping variable \code{grp} (usually a factor).
\item[\code{data}] a data.frame (or list) from which the variables in
\code{formula} should be taken.
\item[\code{na.action}] a function which indicates what should happen
when the data contain \code{NA}s.  The default is to ignore missing
values in either the response or the group.
\item[\code{x}] a list of numeric vectors.
\item[\code{bw}] the smoothing bandwidth, see the manual page for
\code{\LinkA{density}{density}}. If \code{bw} is a character string specifying a rule to choose
the bandwidth, this rule is applied to \code{x[[1]]} and then
the same numerical value of \code{bw} is used throughout.
\item[\code{xlim}] Range of the x axis. If missing, the data range is used.
\item[\code{ylim}] Range of the y axis. If missing, the range of the density
estimates is used.
\item[\code{col}] Line colors. If missing, the
\code{\LinkA{Set1}{Set1}} palette from RColorBrewer
is used.
\item[\code{main}] Plot title.
\item[\code{xlab}] x-axis label.
\item[\code{do.points}] logical; if \code{TRUE}, also draw points at the knot
locations.
\item[\code{subsample}] logical; if \code{TRUE}, subsamples of size 1000 are
used to compute and plot the ecdf for list items with many
observations (\code{>1000})
\item[\code{...}] Further arguments that get passed on to the \code{plot} functions.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
The usefulness of \code{multidensity} can vary,
depending on the data and because of smoothing
artifacts. \code{multiecdf} will in many cases be preferable.
\end{Details}
\begin{Value}
For the \code{multidensity} functions, a list of \code{\LinkA{density}{density}} objects.
\end{Value}
\begin{Author}\relax
Wolfgang Huber \url{http://www.ebi.ac.uk/huber}
\end{Author}
\begin{SeeAlso}\relax
\code{\LinkA{boxplot}{boxplot}},
\code{\LinkA{ecdf}{ecdf}}
\code{\LinkA{density}{density}}
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
  f = 1 + (runif(1000)>0.5)
  x = rnorm(length(f), mean=f, sd=f)
  
  multiecdf(x~f)
  multidensity(x~f)
\end{ExampleCode}
\end{Examples}

