statsmodels.genmod.families.family.Poisson.loglike¶
-
Poisson.
loglike
(endog, mu, scale=1.0)[source]¶ The log-likelihood function in terms of the fitted mean response.
Parameters: endog : array-like
Endogenous response variable
mu : array-like
Fitted mean response variable
scale : float, optional
The scale parameter, defaults to 1.
Returns: llf : float
The value of the loglikelihood function evaluated at (endog,mu,scale) as defined below.
Notes
llf = scale * sum(-mu + endog*log(mu) - gammaln(endog+1)) where gammaln is the log gamma function