Hi all,
I'd just like to tell people that we have a new function package (by yours 
truly) called "basis_functions", that can be used for easily incorporating 
nonlinearity in your models; it also includes a handy function for 
generating Fourier harmonics.
You can find it in the usual place:
http://gretl.sourceforge.net/cgi-bin/gretldata.cgi?opt=SHOW_FUNCS
Of course, comments are welcome.
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   Riccardo (Jack) Lucchetti
   Dipartimento di Scienze Economiche e Sociali (DiSES)
   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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