'transform from the reduced to the full parameter space
Parameters
params_reduced : array_like
parameters in the transformed space
Returns
params : array_like
parameters in the original space
Notes
If the restriction is not homogeneous, i.e. q is not equal to zero,
then this is an affine transform.'

def expand(self, params_reduced):

    params_reduced = np.asarray(params_reduced)
    return (self.transf_mat.dot(params_reduced.T).T + self.constant)
