| % File src/library/stats/man/biplot.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2018 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{biplot} |
| \alias{biplot} |
| \alias{biplot.default} |
| \title{Biplot of Multivariate Data} |
| \usage{ |
| biplot(x, \dots) |
| |
| \method{biplot}{default}(x, y, var.axes = TRUE, col, cex = rep(par("cex"), 2), |
| xlabs = NULL, ylabs = NULL, expand = 1, |
| xlim = NULL, ylim = NULL, arrow.len = 0.1, |
| main = NULL, sub = NULL, xlab = NULL, ylab = NULL, \dots) |
| } |
| \arguments{ |
| \item{x}{The \code{biplot}, a fitted object. For \code{biplot.default}, |
| the first set of points (a two-column matrix), usually associated |
| with observations.} |
| \item{y}{The second set of points (a two-column matrix), usually associated |
| with variables.} |
| \item{var.axes}{If \code{TRUE} the second set of points have arrows |
| representing them as (unscaled) axes.} |
| \item{col}{A vector of length 2 giving the colours for the first and |
| second set of points respectively (and the corresponding axes). If a |
| single colour is specified it will be used for both sets. If |
| missing the default colour is looked for in the |
| \code{\link{palette}}: if there it and the next colour as used, |
| otherwise the first two colours of the palette are used.} |
| \item{cex}{The character expansion factor used for labelling the |
| points. The labels can be of different sizes for the two sets by |
| supplying a vector of length two.} |
| \item{xlabs}{A vector of character strings to label the first set of |
| points: the default is to use the row dimname of \code{x}, or |
| \code{1:n} if the dimname is \code{NULL}.} |
| \item{ylabs}{A vector of character strings to label the second set of |
| points: the default is to use the row dimname of \code{y}, or |
| \code{1:n} if the dimname is \code{NULL}.} |
| \item{expand}{An expansion factor to apply when plotting the second set |
| of points relative to the first. This can be used to tweak the |
| scaling of the two sets to a physically comparable scale.} |
| \item{arrow.len}{The length of the arrow heads on the axes plotted in |
| \code{var.axes} is true. The arrow head can be suppressed by |
| \code{arrow.len = 0}.} |
| \item{xlim, ylim}{Limits for the x and y axes in the units of the |
| first set of variables.} |
| \item{main, sub, xlab, ylab, \dots}{graphical parameters.} |
| } |
| \description{ |
| Plot a biplot on the current graphics device. |
| } |
| \details{ |
| A biplot is plot which aims to represent both the observations and |
| variables of a matrix of multivariate data on the same plot. There are |
| many variations on biplots (see the references) and perhaps the most |
| widely used one is implemented by \code{\link{biplot.princomp}}. |
| The function \code{biplot.default} merely provides the |
| underlying code to plot two sets of variables on the same figure. |
| |
| Graphical parameters can also be given to \code{biplot}: the size of |
| \code{xlabs} and \code{ylabs} is controlled by \code{cex}. |
| } |
| \section{Side Effects}{ |
| a plot is produced on the current graphics device. |
| } |
| \references{ |
| K. R. Gabriel (1971). |
| The biplot graphical display of matrices with application to principal |
| component analysis. |
| \emph{Biometrika}, \bold{58}, 453--467. |
| \doi{10.2307/2334381}. |
| |
| J.C. Gower and D. J. Hand (1996). |
| \emph{Biplots}. |
| Chapman & Hall. |
| } |
| \seealso{\code{\link{biplot.princomp}}, also for examples.} |
| \keyword{hplot} |
| \keyword{multivariate} |