[Gretl-devel] Re: the getinfo() function: request for comments
On Sat, 27 Feb 2021, Allin Cottrell wrote:
First reaction: I'd say this is a case for use of
"catch" rather than having
getinfo return an empty or bogus bundle. An on-the-fly series is just a raw
array of doubles and it seems to me the only information gretl can provide
about it is the numerical values. Well, I suppose we could get a rudimentary
"description" by extracting the argument to getinfo itself as a string:
getinfo(log(sqft)) -> description: "log(sqft)"
But would that serve a purpose?
In fact, I guess it would. The use-case that prompted me to look into this
is using getinfo() within a function, eg
<hansl>
function void foo(series x)
b = getinfo(x)
# do things
end function
</hansl>
To be more specific, I was using getinfo() to check whether the series in
input had some sort of description. Clearly, if you call something like
"foo(log(x))" the function breaks down. Like you say, I could use the
"catch" modifier, but for my taste the catch/$error mechanism should be
reserved for "true" errors (like eg trying to invert a singular matrix)
rather than what we have here. In my view, the input series in this case
has no meaningful metadata, but not's unreasonable to ask for it.
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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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