Reference

All functions
LearnPCA-package LearnPCA	Functions, Data Sets and Vignettes to Aid in Learning Principal Components Analysis (PCA)
PCAtoXhat()	Use PCA Results to Reconstruct All or Part of the Original Data Set
PCsearch()	Demonstrate the Search for New Principal Component Axes
XtoPCAtoXhat()	Reduce a Matrix X via PCA and Reconstruct All or Part to Give Xhat