\Header{summary}{Object Summaries}
\methalias{summary.data.frame}{summary}
\methalias{summary.default}{summary}
\methalias{summary.factor}{summary}
\methalias{summary.matrix}{summary}
\keyword{methods}{summary}
\begin{Description}\relax
\code{summary} is a generic function used to produce result summaries
of the results of various model fitting functions.  The function
invokes particular \code{\Link{methods}} which depend on the
\code{\Link{class}} of the first argument.\end{Description}
\begin{Usage}
\begin{verbatim}
summary(object, ...)

summary.default   (object, ..., digits = max(3, getOption("digits")-3))
summary.data.frame(object, maxsum = 7,
                   digits = max(3, getOption("digits")-3), ...)
summary.factor    (object, maxsum = 100, ...)
summary.matrix    (object, ...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{object}] an object for which a summary is desired.
\item[\code{maxsum}] integer, indicating how many levels should be shown for
\code{\Link{factor}}s.
\item[\code{digits}] integer, used for number formatting with
\code{\Link{signif}()} (for \code{summary.default}) or
\code{\Link{format}()} (for \code{summary.data.frame}).
\item[\code{...}] additional arguments affecting the summary produced.
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
For \code{\Link{factor}}s, the frequency of the first \code{maxsum - 1}
most frequent levels is shown, where the less frequent levels are
summarized in \code{"(Others)"} (resulting in \code{maxsum} frequencies).

The functions \code{summary.lm} and \code{summary.glm} are examples
of particular methods which summarise the results produced by
\code{\Link{lm}} and \code{\Link{glm}}.\end{Details}
\begin{Value}
The form of the value returned by \code{summary} depends on the
class of its argument.  See the documentation of the particular
methods for details of what is produced by that method.\end{Value}
\begin{SeeAlso}\relax
\code{\Link{anova}},
\code{\Link{summary.glm}},
\code{\Link{summary.lm}}.\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
data(attenu)
summary(attenu, digits = 4) #-> summary.data.frame(...), default precision
summary(attenu $ station, maxsum = 20) #-> summary.factor(...)
\end{ExampleCode}
\end{Examples}

