About SsfPack

by Siem Jan Koopman, Neil Shephard and Jurgen A. Doornik

SsfPack is a suite of C routines for carrying out computations involving the statistical analysis of univariate and multivariate models in state space form. The fully implemented link we have made is to Ox 3.0 and higher, the object-oriented matrix programming language of Doornik (1998-2006). It is compatible with the latest Ox 4.0. SsfPack allows for a full range of different state space forms: from a simple time-invariant model to a complicated multivariate time-varying model. Functions are provided to put standard models such as ARIMA, Unobserved components, regressions and cubic spline models into state space form. Basic functions are available for filtering, moment smoothing and simulation smoothing. Ready-to-use functions are provided for standard tasks such as likelihood evaluation, forecasting and signal extraction. SsfPack can be easily used for implementing, fitting and analysing Gaussian models relevant to many areas of econometrics and statistics. Furthermore it provides all relevant tools for the treatment of non-Gaussian and nonlinear state space models. In particular, tools are available to implement simulation based estimation methods such as importance sampling and Markov chain Monte Carlo (MCMC) methods.

About the authors

Siem Jan Koopman is Professor at Free University Amsterdam, Economics Faculty, Department of Econometrics. De Boelelaan 1105, NL-1081 HV Amsterdam, The Netherlands.
Neil Shephard is Professor of Economics at Oxford University and an Official Fellow at Nuffield College, Oxford OX1 1NF, UK.
Jurgen A Doornik is a Research Fellow at Nuffield College, Oxford OX1 1NF, UK. For more information on Ox and GiveWin but also on PcGive and PcFiml, just visit the Doornik work page.

About the SsfPack workpage

The SsfPack workpage at http://www.ssfpack.com is designed and maintained by S.J. Koopman and K.M. Lee. Please send questions, comments and remarks about the website to klee.feweb@gmail.com, with "www.ssfpack.com" in the subject line.

List of SsfPack functions

Models in state space form

AddSsfReg() adds regression effects to time-invariant state space
GetSsfArma() puts ARMA model in state space
GetSsfReg() puts regression model in state space
GetSsfSpline() puts nonparametric cubic spline model in state space
GetSsfStsm() puts unobserved components time series model in state space
SsfCombine() combines system matrices of two models
SsfCombineSym() combines symmetric system matrices of two models

General state space algorithms (for univariate and multivariate models)

KalmanFil() returns output of the Kalman filter
KalmanSmo() returns output of the basic smoothing algorithm
SimSmoDraw() returns a sample from the simulation smoother
SimSmoWgt() returns covariance output of the simulation smoother

Ready-to-use functions (for univariate and multivariate models)

SsfCondDens() returns mean or a draw from the conditional density
SsfLik() returns log-likelihood function
SsfLikConc() returns profile log-likelihood function
SsfLikSco() returns score vector
SsfMomentEst() returns output from prediction, forecasting and smoothing
SsfRecursion() returns output of the state space recursion