PowerLink

class superglm.PowerLink(power: float = 1.0)

Bases: object

Power link: eta = mu^p, mu = eta^(1/p).

Generalises identity (p=1), sqrt (p=0.5), inverse (p=-1), inverse-squared (p=-2). The log link is the p→0 limit but is handled separately for numerical reasons.

Parameters:

powerfloat

The power parameter. Must not be 0 (use LogLink instead).

deriv3_inverse(

eta: NDArray,

) → NDArray

d³μ/dη³ = q(q-1)(q-2)·η^{q-3}, q=1/p. Wood (2011) Appendix D.