statsmodels.genmod.families.links.Power.inverse_deriv2¶ Power.inverse_deriv2(z)[source]¶ Second derivative of the inverse of the power transform Parameters:¶ zarray_likez is usually the linear predictor for a GLM or GEE model. Returns:¶ g^(-1)’(z)ndarrayThe value of the derivative of the inverse of the power transform function