statsmodels.genmod.families.links.InversePower.inverse_deriv¶ InversePower.inverse_deriv(z)¶ 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