[R] PC rotation question

Sasha Pustota
Thu, 25 May 2006 22:03:32 -0000

On p. 48 of "Statistics Complements" to the 3rd MASS edition,
http://www.stats.ox.ac.uk/pub/MASS3/VR3stat.pdf

I read that the orthogonal rotations of Z Lambda^-1 remain
uncorrelated, where Z is the PC and Lambda is the diag matrix of
singular values.

However, the example below that text is

   > A <- loadings(ir.pca) %*% diag(ir.pca$sdev)

If ir.pca$sdev are the singular values, should that be diag(1 /
ir.pca$sdev), or is it some discrepancy between S+ and R that I'm
missing?