| % File src/library/base/man/summary.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2016, 2018 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{summary} |
| \title{Object Summaries} |
| \alias{summary} |
| \alias{summary.default} |
| \alias{summary.data.frame} |
| \alias{summary.factor} |
| \alias{summary.matrix} |
| \alias{format.summaryDefault} |
| \alias{print.summaryDefault} |
| \description{ |
| \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. |
| } |
| \usage{ |
| summary(object, \dots) |
| |
| \method{summary}{default}(object, \dots, digits, quantile.type = 7) |
| \method{summary}{data.frame}(object, maxsum = 7, |
| digits = max(3, getOption("digits")-3), \dots) |
| |
| \method{summary}{factor}(object, maxsum = 100, \dots) |
| |
| \method{summary}{matrix}(object, \dots) |
| |
| \method{format}{summaryDefault}(x, digits = max(3L, getOption("digits") - 3L), \dots) |
| \method{print}{summaryDefault}(x, digits = max(3L, getOption("digits") - 3L), \dots) |
| } |
| \arguments{ |
| \item{object}{an object for which a summary is desired.} |
| \item{x}{a result of the \emph{default} method of \code{summary()}.} |
| \item{maxsum}{integer, indicating how many levels should be shown for |
| \code{\link{factor}}s.} |
| \item{digits}{integer, used for number formatting with |
| \code{\link{signif}()} (for \code{summary.default}) or |
| \code{\link{format}()} (for \code{summary.data.frame}). In |
| \code{summary.default}, if not specified (i.e., |
| \code{\link{missing}(.)}), \code{signif()} will \emph{not} be called |
| anymore (since \R >= 3.4.0, where the default has been changed to |
| only round in the \code{print} and \code{format} methods).}% for "summaryDefault" |
| \item{quantile.type}{integer code used in \code{quantile(*, type=quantile.type)} |
| for the default method.} |
| \item{\dots}{additional arguments affecting the summary produced.} |
| } |
| \details{ |
| For \code{\link{factor}}s, the frequency of the first \code{maxsum - 1} |
| most frequent levels is shown, and the less frequent levels are |
| summarized in \code{"(Others)"} (resulting in at most \code{maxsum} |
| frequencies). |
| |
| The functions \code{summary.lm} and \code{summary.glm} are examples |
| of particular methods which summarize the results produced by |
| \code{\link{lm}} and \code{\link{glm}}. |
| } |
| \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. |
| |
| The default method returns an object of class |
| \code{c("summaryDefault", "\link{table}")} which has specialized |
| \code{\link{format}} and \code{\link{print}} methods. The |
| \code{\link{factor}} method returns an integer vector. |
| |
| The matrix and data frame methods return a matrix of class |
| \code{"\link{table}"}, obtained by applying \code{summary} to each |
| column and collating the results. |
| } |
| \seealso{ |
| \code{\link{anova}}, |
| \code{\link{summary.glm}}, |
| \code{\link{summary.lm}}. |
| } |
| \references{ |
| Chambers, J. M. and Hastie, T. J. (1992) |
| \emph{Statistical Models in S}. |
| Wadsworth & Brooks/Cole. |
| } |
| \examples{ |
| summary(attenu, digits = 4) #-> summary.data.frame(...), default precision |
| summary(attenu $ station, maxsum = 20) #-> summary.factor(...) |
| |
| lst <- unclass(attenu$station) > 20 # logical with NAs |
| ## summary.default() for logicals -- different from *.factor: |
| summary(lst) |
| summary(as.factor(lst)) |
| } |
| \keyword{methods} |