def _sym_decorrelation(W):
 K = np.dot(W, W.T)
 (s, u) = np.linalg.eigh(K)
 (u, W) = [np.asmatrix(e) for e in (u, W)]
 W = (((u * np.diag((1.0 / np.sqrt(s)))) * u.T) * W)
 return W

def _sym_decorrelation ( W ) : K = np . dot ( W , W . T ) ( s , u ) = np . linalg . eigh ( K ) ( u , W ) = [ np . asmatrix ( e ) for e in ( u , W ) ] W = ( ( ( u * np . diag ( ( 1.0 / np . sqrt ( s ) ) ) ) * u . T ) * W ) return W
symmetric decorrelation i .