statsmodels.discrete.discrete_model.NegativeBinomial.loglike¶
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NegativeBinomial.
loglike
(params)[source]¶ Loglikelihood for negative binomial model
Parameters: params : array-like
The parameters of the model. If loglike_method is nb1 or nb2, then the ancillary parameter is expected to be the last element.
Returns: llf : float
The loglikelihood value at params
Notes
Following notation in Greene (2008), with negative binomial heterogeneity parameter :
where :math`Q=0` for NB2 and geometric and for NB1. For the geometric, as well.