def null_beta_covariance(self):
        """
        Covariance of the optimal 𝜷 according to the marginal likelihood.

        Returns
        -------
        beta_covariance : ndarray
            (Xᵀ(s(K + vI))⁻¹X)⁻¹.
        """
        A = sum(i @ j.T for (i, j) in zip(self._XTQDi, self._XTQ))
        return self.null_scale * pinv(A)
def null_beta_covariance(self):
        """
        Covariance of the optimal 𝜷 according to the marginal likelihood.

        Returns
        -------
        beta_covariance : ndarray
            (Xᵀ(s(K + vI))⁻¹X)⁻¹.
        """
        A = sum(i @ j.T for (i, j) in zip(self._XTQDi, self._XTQ))
        return self.null_scale * pinv(A)
def null_beta_covariance ( self ) : A = sum ( i @ j . T for ( i , j ) in zip ( self . _XTQDi , self . _XTQ ) ) return self . null_scale * pinv ( A )
Covariance of the optimal 𝜷 according to the marginal likelihood.

        Returns
        -------
        beta_covariance : ndarray
            (Xᵀ(s(K + vI))⁻¹X)⁻¹.
Covariance of the optimal 𝜷 according to the marginal likelihood .