def variance_K(K, verbose=False):
    """estimate the variance explained by K"""
    c = SP.sum((SP.eye(len(K)) - (1.0 / len(K)) * SP.ones(K.shape)) * SP.array(K))
    scalar = (len(K) - 1) / c
    return 1.0/scalar
def variance_K ( K , verbose = False ) : c = SP . sum ( ( SP . eye ( len ( K ) ) - ( 1.0 / len ( K ) ) * SP . ones ( K . shape ) ) * SP . array ( K ) ) scalar = ( len ( K ) - 1 ) / c return 1.0 / scalar
estimate the variance explained by K