On Tue, 8 Dec 2015, Riccardo (Jack) Lucchetti wrote:
 Ah, for future reference: there's a much more efficient way to do
the same: 
 instead of
        $i_med = replace(unit, M[,1], M[,j++])
 you can use
        $i_med2 = pexpand(M[,j++])
 which is of course more general but much faster. 
Sorry, I meant: LESS general but much faster. Doh!
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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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