statsmodels.tsa.statespace.mlemodel.MLEModel

class statsmodels.tsa.statespace.mlemodel.MLEModel(endog, k_states, exog=None, dates=None, freq=None, **kwargs)

State space model for maximum likelihood estimation

Parameters

endogarray_like

The observed time-series process \(y\)

k_statesint

The dimension of the unobserved state process.

exogarray_like, optional

Array of exogenous regressors, shaped nobs x k. Default is no exogenous regressors.

datesarray-like of datetime, optional

An array-like object of datetime objects. If a Pandas object is given for endog, it is assumed to have a DateIndex.

freqstr, optional

The frequency of the time-series. A Pandas offset or ‘B’, ‘D’, ‘W’, ‘M’, ‘A’, or ‘Q’. This is optional if dates are given.

**kwargs

Keyword arguments may be used to provide default values for state space matrices or for Kalman filtering options. See Representation, and KalmanFilter for more details.

See also

MLEResults, statsmodels.tsa.statespace.kalman_filter.KalmanFilter, statsmodels.tsa.statespace.representation.Representation

Notes

This class wraps the state space model with Kalman filtering to add in functionality for maximum likelihood estimation. In particular, it adds the concept of updating the state space representation based on a defined set of parameters, through the update method or updater attribute (see below for more details on which to use when), and it adds a fit method which uses a numerical optimizer to select the parameters that maximize the likelihood of the model.

The start_params update method must be overridden in the child class (and the transform and untransform methods, if needed).

Attributes

ssmstatsmodels.tsa.statespace.kalman_filter.KalmanFilter

Underlying state space representation.

Methods

filter(params[, transformed, complex_step, …])	Kalman filtering
fit([start_params, transformed, cov_type, …])	Fits the model by maximum likelihood via Kalman filter.
from_formula(formula, data[, subset])	Not implemented for state space models
hessian(params, *args, **kwargs)	Hessian matrix of the likelihood function, evaluated at the given parameters
impulse_responses(params[, steps, impulse, …])	Impulse response function
information(params)	Fisher information matrix of model
initialize()	Initialize (possibly re-initialize) a Model instance.
initialize_approximate_diffuse([variance])	Initialize approximate diffuse
initialize_known(initial_state, …)	Initialize known
initialize_statespace(**kwargs)	Initialize the state space representation
initialize_stationary()	Initialize stationary
loglike(params, *args, **kwargs)	Loglikelihood evaluation
loglikeobs(params[, transformed, complex_step])	Loglikelihood evaluation
observed_information_matrix(params[, …])	Observed information matrix
opg_information_matrix(params[, …])	Outer product of gradients information matrix
predict(params[, exog])	After a model has been fit predict returns the fitted values.
prepare_data()	Prepare data for use in the state space representation
score(params, *args, **kwargs)	Compute the score function at params.
score_obs(params[, method, transformed, …])	Compute the score per observation, evaluated at params
set_conserve_memory([conserve_memory])	Set the memory conservation method
set_filter_method([filter_method])	Set the filtering method
set_inversion_method([inversion_method])	Set the inversion method
set_smoother_output([smoother_output])	Set the smoother output
set_stability_method([stability_method])	Set the numerical stability method
simulate(params, nsimulations[, …])	Simulate a new time series following the state space model
simulation_smoother([simulation_output])	Retrieve a simulation smoother for the state space model.
smooth(params[, transformed, complex_step, …])	Kalman smoothing
transform_jacobian(unconstrained[, …])	Jacobian matrix for the parameter transformation function
transform_params(unconstrained)	Transform unconstrained parameters used by the optimizer to constrained parameters used in likelihood evaluation
untransform_params(constrained)	Transform constrained parameters used in likelihood evaluation to unconstrained parameters used by the optimizer
update(params[, transformed, complex_step])	Update the parameters of the model