Using Theorem 3.15 show that PC correlation loadings extracted from a covariance matrix are identical to those from a correlation matrix if the variances of the variables are equal
THEOREM 3.15
Let X be a (n x p) data matrix such that 1= 2= • • • = p =0, and where XTX has latent roots L and latent vectors P. Then for some scalar c,
(i) cXTX has latent roots cL and latent vectors P.
(ii) XTX + cl has latent roots L + cI and latent vectors P.
(iii) (XTX) c has latent roots Lc and latent vectors P.