Gavin Simpson
2003-Feb-11 18:50 UTC
[R] Dynamic Linear Models for Times Series - Implemented?
Hi, I was wondering whether a package that can perform dynamic linear models on times series data was available for R? Many Thanks, Gavin Simpson %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Gavin Simpson [T] +44 (0)20 7679 5522 ENSIS Research Fellow [F] +44 (0)20 7679 7565 ENSIS Ltd. & ECRC [E] gavin.simpson at ucl.ac.uk UCL Department of Geography 26 Bedford Way London. WC1H 0AP. %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
Gavin Simpson
2003-Feb-12 14:16 UTC
[R] Dynamic Linear Models for Times Series - Implemented?
Hi, Following an off-list reply to my original post, I realised that I hadn't really provided very much information for you to work with. So here's a second attempt: Following West & Harrison (1989) and Pole et al. (1994) a DLM is defined as: Y[t] = F'[t]theta[t] + v[t], v[t] ~ N[0,V] #Observation equation theta[t] = G[t]theta[t-1] + w[t], w[t] ~ N[0,W] #system equation The system equation is a first order Markov process, where G[t] is a matrix of known coefficients that defines the systematic evolution of the state vector (theta[t]) across time, and w[t] is an unobservable stochastic error term having a normal distribution with zero mean and covariance matrix. Y[t] denotes the observation series at time t F[t] is a vector of known constants (the regression vector) theta[t] denotes the vector of model state parameters v[t] is a stochastic error term having zero mean and variance V[t] If I have understood Brockwell and Davis (1991) correctly, the DLM can be considered from the point of view of State-space models (although I am venturing some way out of my statistical depth here, all the papers I have collected are applied examples and they all refer to dynamic Linear Models, not State-space models). It seems that some of this has been done in S (for S-Plus), as I found the bts package by Harrison and Reed on StatLib (http://lib.stat.cmu.edu/DOS/S/), "SPLUS for Windows functions and datasets for Bayesian forecasting based on the algorithms in Bayesian Forecasting and Dynamic Linear Models by West and Harrison" So I was wondering whether anyone knew of existing R code that could fit such models? Many thanks Gavin Simpson Refs: Brockwell and Davis (1991). Time Series: Theory and Methods. Springer Pole, West and Harrison (1994). Applied Bayesian Forecasting and Time Series Analysis. Chapman & Hall/CRC West and Harrison (1989). Bayesian Forecasting and Dynamic Models. Springer -----Original Message----- From: r-help-admin at stat.math.ethz.ch [mailto:r-help-admin at stat.math.ethz.ch] On Behalf Of Gavin Simpson Sent: 11 February 2003 17:49 To: r-help Subject: [R] Dynamic Linear Models for Times Series - Implemented? Hi, I was wondering whether a package that can perform dynamic linear models on times series data was available for R? Many Thanks, Gavin Simpson %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Gavin Simpson [T] +44 (0)20 7679 5522 ENSIS Research Fellow [F] +44 (0)20 7679 7565 ENSIS Ltd. & ECRC [E] gavin.simpson at ucl.ac.uk UCL Department of Geography 26 Bedford Way London. WC1H 0AP. %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% ______________________________________________ R-help at stat.math.ethz.ch mailing list http://www.stat.math.ethz.ch/mailman/listinfo/r-help