biplot {mva} | R Documentation |

Plot a biplot on the current graphics device.

biplot(x, ...) ## Default S3 method: 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, ...)

`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 paletter 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` is 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` is 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. |

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`

.

a plot is produced on the current graphics device.

K. R. Gabriel (1971). The biplot graphical display of matrices with
application to principal component analysis. *Biometrika*
**58**, 453–467.

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

`biplot.princomp`

, also for examples.