# biplot

##### Biplot of Multivariate Data

Plot a biplot on the current graphics device.

- Keywords
- multivariate, hplot

##### Usage

`biplot(x, …)`# S3 method for default
biplot(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, …)

##### Arguments

- x
The

`biplot`

, a fitted object. For`biplot.default`

, the first set of points (a two-column matrix), usually associated with observations.- y
The second set of points (a two-column matrix), usually associated with variables.

- var.axes
If

`TRUE`

the second set of points have arrows representing them as (unscaled) axes.- 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

`palette`

: if there it and the next colour as used, otherwise the first two colours of the palette are used.- 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.

- xlabs
A vector of character strings to label the first set of points: the default is to use the row dimname of

`x`

, or`1:n`

if the dimname is`NULL`

.- ylabs
A vector of character strings to label the second set of points: the default is to use the row dimname of

`y`

, or`1:n`

if the dimname is`NULL`

.- 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.

- arrow.len
The length of the arrow heads on the axes plotted in

`var.axes`

is true. The arrow head can be suppressed by`arrow.len = 0`

.- xlim, ylim
Limits for the x and y axes in the units of the first set of variables.

- main, sub, xlab, ylab, …
graphical parameters.

##### 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 `biplot.princomp`

.
The function `biplot.default`

merely provides the
underlying code to plot two sets of variables on the same figure.

Graphical parameters can also be given to `biplot`

: the size of
`xlabs`

and `ylabs`

is controlled by `cex`

.

##### 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.
*Biometrika*, **58**, 453--467.
10.2307/2334381.

J.C. Gower and D. J. Hand (1996).
*Biplots*.
Chapman & Hall.

##### See Also

`biplot.princomp`

, also for examples.

*Documentation reproduced from package stats, version 3.5.0, License: Part of R 3.5.0*