* Principal dimension is getTop(). Next greatest eigenvector is getTop()-1.
* Note - pca.getComponents starts counting the spectrum from rank-2 to zero,
* rather than rank-1, so getComponents(dimN ...) == updateRcView(dimN+1 ..)
* Principal dimension is getTop(). Next greatest eigenvector is getTop()-1.
* Note - pca.getComponents starts counting the spectrum from rank-2 to zero,
* rather than rank-1, so getComponents(dimN ...) == updateRcView(dimN+1 ..)