[Gretl-users] Replay on case-sensivity

Here's a more extended reply to Berend Hasselman's posts on case-sensitivity with regard to variable names in gretl. First, I've now modified the Find dialog for the gretl main window so that it gives the option of a case-sensitive search on variable names only. (I suppose a common use of this dialog is to find strings anywhere in the window, including in the descriptions of variables, in which case a case-insensitive search is appropriate.) Now to Berend's request that gretl should ignore case when handling variable names. One point to be made here is that this would be a backward-incompatible change, and a rather devastating one: I know that it would break a _lot_ of the gretl scripts on my system. That's not a killer argument for staying with the status quo, but it means there has to be a rather compelling reason for change. I don't see a compelling reason; in fact, I think that on balance the argument for case sensitivity outweighs the arguments against (disregarding the compatibility issue). As I see it there are three possible arguments for ignoring case: (1) Case sensitivity can make it inconvenient to deal with third-party datasets that use mixed case for variable names. It would be more convenient if one could assume that when "foobar" is typed in gretl this will automatically map onto a variable named "FooBar" in imported data. Comment: Granted, this can be a (minor) inconvenience. But any decent text editor has an option to adjust the case of selected text, so for plain text data files this shouldn't really be an issue. It _might_ be worth adding an option in gretl to convert all variable names to lower case. (2) The possibility of having variables whose names differ only in respect of case creates potential for confusion: how to keep "cpi", "CPI" and "Cpi" straight? Comment: Use a sane policy in naming variables (but see below). (3) Users of MS Windows are unused to case sensitivity and may find the effects surprising. Comment: Yes, but it doesn't take long to learn. Now here's the positive argument in favour of case sensitivity. The issue of "sensitive or not" mostly arises in the context of scripts, where variable names have to be typed rather than "clicked on". That is, it mostly arises when gretl is being used as a programming language. OK, programming languages differ with regard to case sensitivity, but many of the best and most widespread ones respect case (C and Java, for instance). And in an econometric context it seems to me very natural to expect case sensitivity, as one finds it in mathematical notation. Here are just a few examples: t = time index; T = maximum value of t i = index variable; I = identity matrix Y = output; y = log of output m = scalar; M = matrix People's expectations may differ, but I would very definitely not want to see these uses of case broken. -- Allin Cottrell Department of Economics Wake Forest University