@property<EOL><INDENT>def B(self):<DEDENT>
self._terms<EOL>return asarray(self._mean.B, float)<EOL>
Fixed-effect sizes B from 𝐦 = (A ⊗ X) vec(B).

Returns
-------
fixed-effects : ndarray
    B from 𝐦 = (A ⊗ X) vec(B).