[R] PC rotation question
Sasha Pustota
popgen at gmail.com
Fri May 26 00:03:32 CEST 2006
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?
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