Re: [Gretl-devel] members of lists returned from functions
On Mon, 11 Feb 2008, Allin Cottrell wrote:
But what about successive invocations:
logs xlist
logs zlist
where xlist and zlist contain long names that will yield
"cross-conflicting" log names, so to speak? Under the new
proposal as it stands, some of the logs created by the first
command would be overwritten (I think).
And rightly so, if you ask me. Now, we may consider raising VNAMELEN to
24 or 32 to minimise the chances of this happening, but then formatting
the output of estimation commands becomes a problem. The Stata guys
solved this issue by truncating variable names on output, using
reasonable conventions. Example:
. regress very_long_identifier_y very_long_identifier1 very_long_identifier2
Source | SS df MS Number of obs = 753
-------------+------------------------------ F( 2, 750) = 45.82
Model | 860.569119 2 430.284559 Prob > F = 0.0000
Residual | 7042.54159 750 9.39005546 R-squared = 0.1089
-------------+------------------------------ Adj R-squared = 0.1065
Total | 7903.11071 752 10.5094557 Root MSE = 3.0643
------------------------------------------------------------------------------
very_long_~y | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
very_long~_1 | -.1177097 .0467719 -2.52 0.012 -.209529 -.0258903
very_long_~2 | .5480657 .061962 8.85 0.000 .4264261 .6697053
_cons | -2.889082 .623721 -4.63 0.000 -4.113529 -1.664636
------------------------------------------------------------------------------
Perhaps we could do the same.
But maybe worrying about this falls into the category of trying a
little too hard to stop users from shooting themselves in the
foot.
We can ensure the docs are clear on this point, and leave it up to
the user to use variable names of a sane length. Maybe also print
a message when an existing variable is redefined via an
auto-naming command/function.
I heartily agree.
Riccardo (Jack) Lucchetti
Dipartimento di Economia
Università Politecnica delle Marche
r.lucchetti(a)univpm.it
http://www.econ.univpm.it/lucchetti