A randomly selected disk before (left) and after (right) the whitening operation. The samples are strongly correlated and thus unsuitable for the K-S test before the transformation, but afterwards no correlations are visible and the variance is 1. Note that whitening the data does not mean that we are “forcing” the K-S test to pass. The whitened data will only end up matching N(0,1) after whitening if they followed our theoretical distribution N(0,C) before.