Displaying 1 result from an estimated 1 matches for "scaledusarrests".
2011 Jun 30
2
sdev value returned by princomp function (used for PCA)
...p it says 'sdev' is 'the standard deviations of the principal components'.
However, when I calculate the principal components for the USArrests data set, I don't find this to be the case:
Here is how I calculated the principal components and got the 'sdev' values:
> scaledUSArrests <- scale(USArrests) # standardise the variables to have variance 1 and mean 0
> myPCA <- princomp(scaledUSArrests) # do the PCA
> myPCA$sdev
Comp.1 Comp.2 Comp.3 Comp.4
1.5590500 0.9848705 0.5911277 0.4122639
As far as I understand, the principal components themselves ar...