screeplot {stats} | R Documentation |

## Screeplots

### Description

`screeplot.default`

plots the variances against the number of the
principal component. This is also the `plot`

method for classes
`"princomp"`

and `"prcomp"`

.

### Usage

## Default S3 method:
screeplot(x, npcs = min(10, length(x$sdev)),
type = c("barplot", "lines"),
main = deparse(substitute(x)), ...)

### Arguments

`x` |
an object containing a `sdev` component, such as that
returned by `princomp()` and `prcomp()` . |

`npcs` |
the number of components to be plotted. |

`type` |
the type of plot. |

`main, ...` |
graphics parameters. |

### References

Mardia, K. V., J. T. Kent and J. M. Bibby (1979).
*Multivariate Analysis*, London: Academic Press.

Venables, W. N. and B. D. Ripley (2002).
*Modern Applied Statistics with S*, Springer-Verlag.

### See Also

`princomp`

and `prcomp`

.

### Examples

## The variances of the variables in the
## USArrests data vary by orders of magnitude, so scaling is appropriate
(pc.cr <- princomp(USArrests, cor = TRUE)) # inappropriate
screeplot(pc.cr)
fit <- princomp(covmat=Harman74.cor)
screeplot(fit)
screeplot(fit, npcs=24, type="lines")

[Package

*stats* version 2.5.0

Index]