Plot a PCA object returned by prcomp

Usage

pcaplot(
  pca,
  components = 1:2,
  group = NULL,
  col = NULL,
  pch = 19,
  cex = 2,
  legend = NULL,
  ...
)

pca: PCA object returned by prcomp
components: a vector of length two indicating the components to plot
group: a factor determining shapes of the points to show (unless overriden by pch=...)
col: Color for plotting (default: internal palette)
pch: Type of character to plot (default: 19)
cex: size of the symbols used for plotting
legend: draw a legend? If legend is a position (eg. "topright"), then a legend is drawn. If NULL or if the group parameter is NULL, then not.
...: any further parameters will be passed to the plot() function (e.g. col, cex, ...)

If group is NULL, then NULL; else a data frame containing colors and shapes matching each group

This is a simplistic function. A much better way is to use the pca2d function from the pca3d package.