# Biplot for Principal Components (objects of class 'Pca')

### Description

Produces a biplot from an object (derived from) `Pca-class`

.

### Usage

1 2 |

### Arguments

`x` |
an object of class (derived from) |

`choices` |
length 2 vector specifying the components to plot. Only the default is a biplot in the strict sense. |

`scale` |
The variables are scaled by |

`...` |
optional arguments to be passed to the internal graphical functions. |

### Side Effects

a plot is produced on the current graphics device.

### Methods

- biplot
`signature(x = Pca)`

: Plot a biplot, i.e. represent both the observations and variables of a matrix of multivariate data on the same plot. See also`biplot.princomp`

.

### References

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

### See Also

`Pca-class`

,
`PcaClassic`

,
`PcaRobust-class`

.

### Examples

1 2 | ```
require(graphics)
biplot(PcaClassic(USArrests, k=2))
``` |