statsmodels.genmod.families.family.Gamma.loglike_obs¶
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Gamma.
loglike_obs
(endog, mu, var_weights=1.0, scale=1.0)[source]¶ The log-likelihood function for each observation in terms of the fitted mean response for the Gamma distribution.
Parameters: Returns: ll_i – The value of the loglikelihood evaluated at (endog, mu, var_weights, scale) as defined below.
Return type: Notes
\[ll_i = var\_weights_i / scale * (\ln(var\_weights_i * endog_i / (scale * \mu_i)) - (var\_weights_i * endog_i) / (scale * \mu_i)) - \ln \Gamma(var\_weights_i / scale) - \ln(\mu_i)\]