The FA can reach a maximum value of 1 ( this rarely happens in real data ) , in which case D has only one nonzero eigenvalue .
The ellipsoid reduces to a line in the direction of that eigenvector .
The FA can reach a maximum value of 1 ( this rarely happens in real data ) , in which case D has only one nonzero eigenvalue and the ellipsoid reduces to a line in the direction of that eigenvector .