statsmodels.genmod.families.family.Poisson

class statsmodels.genmod.families.family.Poisson(link=None)[source]

Poisson exponential family.

Parameters:link (a link instance, optional) – The default link for the Poisson family is the log link. Available links are log, identity, and sqrt. See statsmodels.families.links for more information.

The link function of the Poisson instance.

Type:a link instance
variance

variance is an instance of statsmodels.genmod.families.varfuncs.mu

Type:varfuncs instance

Methods

deviance(endog, mu[, var_weights, …]) The deviance function evaluated at (endog, mu, var_weights, freq_weights, scale) for the distribution.
fitted(lin_pred) Fitted values based on linear predictors lin_pred.
loglike(endog, mu[, var_weights, …]) The log-likelihood function in terms of the fitted mean response.
loglike_obs(endog, mu[, var_weights, scale]) The log-likelihood function for each observation in terms of the fitted mean response for the Poisson distribution.
predict(mu) Linear predictors based on given mu values.
resid_anscombe(endog, mu[, var_weights, scale]) The Anscombe residuals
resid_dev(endog, mu[, var_weights, scale]) The deviance residuals
starting_mu(y) Starting value for mu in the IRLS algorithm.
weights(mu) Weights for IRLS steps