whether is it an error in computing the gauss of mix_gaussian?

[wgfi110]

in prml/rv/multivariate_gaussian_mixture.py:124
the origin is :
D_sq = np.sum(np.einsum('nki,kij->nkj', d, self.cov) * d, -1)
should be changed to:
D_sq = np.sum(np.einsum('nki,kij->nkj', d, np.linalg.inv(self.cov)) * d, -1)