Re: [Gretl-users] aggregate by
On Tue, 19 Feb 2013, Allin Cottrell wrote:
> Mmmm. I like it. This as a native function would be very nice to
have.
> Plus, this is one of those cases in which C would be much much faster than
> hansl.
Agreed. In tonight's CVS we have a native function, aggregate(), on the
pattern shown above, which supports the methods sum, mean, sd, var, sst,
skewness, kurtosis, min, max, median and gini. It'll be in the snapshots
tomorrow.
Very nice. The next step, logically, would be to support user-written
functions too. However, this would mean to complicate the code by a factor
(I reckon) of 1 to 5 or so. Arguably though, this would only be useful in
a few cases, since if you take the trouble to write a complex user-level
funciton to accomplish something very specific, then the overhead of
aggregating "by hand", as in Allin's hansl script he sent yesterday
becomes negligible.
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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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