'Compute orthogonalized MA coefficient matrices using P matrix such
that :math:`\Sigma_u = PP^\prime`. P defaults to the Cholesky
decomposition of :math:`\Sigma_u`
Parameters
maxn : int
Number of coefficient matrices to compute
P : ndarray (k x k), optional
Matrix such that Sigma_u = PP\', defaults to Cholesky descomp
Returns
coefs : ndarray (maxn x k x k)'

def orth_ma_rep(self, maxn=10, P=None):

    return orth_ma_rep(self, maxn, P)
