pcaMethods (version 1.64.0)

biplot-methods: Plot a overlaid scores and loadings plot

Description

Visualize two-components simultaneously

Usage

"biplot"(x, choices = 1:2, scale = 1, pc.biplot = FALSE, ...)
"biplot"(x, choices = 1:2, scale = 1, pc.biplot = FALSE, ...)

Arguments

x
a pcaRes object
choices
which two pcs to plot
scale
The variables are scaled by $lambda^scale$ and the observations are scaled by $lambda ^ (1-scale)$ where lambda are the singular values as computed by princomp. Normally $0
pc.biplot
If true, use what Gabriel (1971) refers to as a "principal component biplot", with $lambda = 1$ and observations scaled up by sqrt(n) and variables scaled down by sqrt(n). Then the inner products between variables approximate covariances and distances between observations approximate Mahalanobis distance.
...
optional arguments to be passed to biplot.default.

Value

a plot is produced on the current graphics device.

Details

This is a method for the generic function 'biplot'. There is considerable confusion over the precise definitions: those of the original paper, Gabriel (1971), are followed here. Gabriel and Odoroff (1990) use the same definitions, but their plots actually correspond to pc.biplot = TRUE.

See Also

prcomp, pca, princomp

Examples

Run this code
data(iris)
pcIr <- pca(iris[,1:4])
biplot(pcIr)

Run the code above in your browser using DataLab