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

NegativeBinomial.deriv2(p)[source]¶

Second derivative of the negative binomial link function.

Parameters:

p : array-like

Mean parameters

Returns:

g’‘(p) : array

The second derivative of the negative binomial transform link function

Notes

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