statsmodels.discrete.count_model.ZeroInflatedPoissonResults.set_null_options

method

ZeroInflatedPoissonResults.set_null_options(llnull=None, attach_results=True, **kwds)

set fit options for Null (constant-only) model

This resets the cache for related attributes which is potentially fragile. This only sets the option, the null model is estimated when llnull is accessed, if llnull is not yet in cache.

Parameters

llnullNone or float

If llnull is not None, then the value will be directly assigned to the cached attribute “llnull”.

attach_resultsbool

Sets an internal flag whether the results instance of the null model should be attached. By default without calling this method, thenull model results are not attached and only the loglikelihood value llnull is stored.

kwdskeyword arguments

kwds are directly used as fit keyword arguments for the null model, overriding any provided defaults.

Returns

no returns, modifies attributes of this instance