On Thu, December 21, 2006 13:54, Sven Schreiber wrote:
Allin Cottrell schrieb:
>
> The estimators you mention are good candidates for inclusion at some
> point, but I don't know how soon -- there are lots of things to be done
> and only two of us actually coding on gretl.
>
> Allin.
>
I am certainly not against including new features in gretl, but given
the scarce resources, maybe Jack and you should think of a policy that
determines when a new feature should be implemented via the great new
function package mechanism (i.e. doable by many others), and when it has
to be coded (in C) in gretl itself (i.e. Allin or Jack have to do it).
I'm personally inclined to say that from now on everything that can reasonably
done via a user function should be done that way. I say "reasonably" because
our scripting infrastructure is, as of now, not sophisticated enough to
support computationally demanding methods. For example, there is now in CVS a
pretty decent implementation of Arellano & Bond's estimator for dynamic
panels, which would have been impossible to do via a script. But in the end,
it's a bit of a chicken-and-egg problem; gretl's scripting capabilities have
increased enormously in a year or so exactly because we started using
user-level functions for doing things and discovered what was missing during
the process. The other day, I wrote a little function to extract long-run
coefficients from an ADL model (attached for those interested), which exposed
a bug in the matrix code, now fixed in CVS.
The more people write functions, the more enhancements and bug fixes are
likely to come in the future -> the easier it becomes to rely on user-level
functions for doing stuff.
<Shameless plug:> Of course, allowing shell commands in
functions would
greatly expand the scope of function packages by using existing
algorithms in R etc. But it sounded like I already got your "okay" on
that...
This is already in CVS.
Riccardo (Jack) Lucchetti
Dipartimento di Economia
Facoltà di Economia "G. Fuà"
Ancona