statsmodels.genmod.families.family.Poisson¶

class statsmodels.genmod.families.family.Poisson(link=None, check_link=True)[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.

check_linkbool

If True (default), then and exception is raised if the link is invalid for the family. If False, then the link is not checked.

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

variance

See also

statsmodels.genmod.families.family.Family

Parent class for all links.

Link Functions

Further details on links.

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.
get_distribution(mu[, scale, var_weights])	Frozen Poisson distribution instance for given parameters
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