statsmodels.genmod.families.links.NegativeBinomial.deriv2¶

NegativeBinomial.deriv2(p)[source]¶

Second derivative of the negative binomial link function.

Parameters:¶

parray_like

Mean parameters

Returns:¶

g’’(p)ndarray

The second derivative of the negative binomial transform link function

Notes

g’’(x) = -(1+2*alpha*x)/(x+alpha*x^2)^2