On Mon, 23 Apr 2012, Summers, Peter wrote:
 AFAIK, this is one you'd have to do yourself via MLE (or GMM,
maybe?). I 
 think that JMulti has this class of model available from a menu or 
 something similar, but I've never used it. 
Among the function packages you find on gretl's servewr there is a package 
for estimating SETAR models by Federico Lampis and Ignacio Díaz-Emparanza. 
Maybe you can use that as a starting point for your own code.
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  Riccardo (Jack) Lucchetti
  Dipartimento di Economia
  Università Politecnica delle Marche
  (formerly known as Università di Ancona)
  r.lucchetti(a)univpm.it
  
http://www2.econ.univpm.it/servizi/hpp/lucchetti
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