statsmodels.genmod.families.family.Poisson

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

Poisson exponential family.

Parameters
linka 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.

See also

statsmodels.genmod.families.family.Family

Parent class for all links.

Link Functions

Further details on links.

Attributes
Poisson.linka link instance

The link function of the Poisson instance.

Poisson.variancevarfuncs instance

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

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.

variance

weights(mu)

Weights for IRLS steps

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

Properties

link

Link function for family

links

safe_links

valid

variance