Plot Principal Components

Plot the first three PCs and draw ellipses highlighting differences in the levels of a factor

Usage

PCAplot(by, tdat)

Arguments

by

factor to plot as ellipses on PCA plots

tdat

data matrix to compute principal components

Value

PCA plots for every combination of PC1, PC2, and PC3. The percentage of variation contribution is shown in the axes labels.

Author

Aline Talhouk, Derek Chiu

Examples

PCAplot(mtcars$cyl, mtcars)

PCAplot(mtcars$gear, mtcars)