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depmixS4 (version 0.2-1)

depmixS4-package: depmixS4 provides classes for specifying and fitting hidden Markov models

Description

depmixS4 is a framework for specifying and fitting dependent mixture models, otherwise known as hidden or latent Markov models. Optimization is done with the EM algorithm or optionally with Rdonlp2 when (general linear (in-)equality) constraints on the parameters need to be incorporated. Models can be fitted on (multiple) sets of observations. The response densities for each state may be chosen from the GLM family, or a multinomial. User defined response densities are easy to add. Mixture or latent class (regression) models can also be fitted; these are the limit case in which the length of observed time series is 1 for all cases.

Arguments

Details

ll{ Package: depmixS4 Type: Package Version: 0.2-0 Date: 2008-06-10 License: GPL }

Model fitting is done in two steps; first, models are specified through the depmix function (or the mix function for mixture and latent class models), which both use standard glm style arguments to specify the observed distributions; second, the model needs to be fitted by using the fit function; imposing constraints is done through the fit function. Standard output includes the optimized parameters and the posterior densities for the states and the optimal state sequence.

References

On hidden Markov models: Lawrence R. Rabiner (1989). A tutorial on hidden Markov models and selected applications in speech recognition. Proceedings of IEEE, 77-2, p. 267-295.

On latent class models: A. L. McCutcheon (1987). Latent class analysis. Sage Publications.

See Also

depmix, fit

Examples

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