Re: [Gretl-devel] [Gretl-users] Trouble in deleting variables
Am 10.12.2010 21:25, schrieb Allin Cottrell:
The ID number of a series in gretl is simply the 0-based position
of that series in a two-dimensional array of double-precision
values. If a given series is deleted, it's inevitable that
higher-numbered series will be relocated and hence renumbered --
unless we were to permit holes in the dataset, which would be a
programming nightmare.
Neither IMO, does it make any sense to keep two sets of books, one
recording where variables actually are and another for some sort
of cosmetic purpose; the mapping between these two would be an
obvious source of errors, crashes and so on.
Well it's not really only cosmetic, see the issue that started this
thread. And this kind of two-book-concept is usually denominated by the
obscure name of a "database" with "keys" :-) The DBMS (database
management system) keeps track of the memory chunks to which the
immutable keys should point.
Anyway, given the current status quo it may well be that it's best to
leave the whole thing as it is. I tend to agree that the user-level
constraints are not a big problem (unless somebody else comes up with
more annoying examples). But if we were to discuss the design as such,
I would argue for a database-like solution without those constraints.
cheers,
sven