[Gretl-devel] Bug in help file

[Riccardo (Jack) Lucchetti]

On Wed, 12 Sep 2007, Allin Cottrell wrote:

> On Wed, 12 Sep 2007, andreas.rosenblad at ltv.se wrote:
>
>> The help file for Nonlinear Least Squares needs to be changed. In the
>> example it gives it says that one could use the following code in the NLS
>> window...
>
>> However, this results in the following error message: 'gamma' refers to a
>> function and may not be used as a variable name
>>
>> It is pedagogically bad to have an example that does not work.
>
> Yes, clearly so.
>
> I will first see how difficult it is to make function names and
> variable names non-colliding (that is, it would be nice to be able
> to use "gamma" for a variable, and in principle that should be
> possible).  But if that looks too complicated I'll change the
> manual.

"Gamma" is a rather special case. Of all Greek letters, it's the only one 
that's more likely to be used to indicate a function than a parameter (or 
at least 50/50). The solution I have used for years is to use "gama" with 
1 "m" for parameters --- which does look ugly, but saves you incidents 
like this. Or, we could possibly take advantage of gretl being case 
sensitive and use "Gamma" (capital g) in the example.


Riccardo (Jack) Lucchetti
Dipartimento di Economia
Università Politecnica delle Marche

r.lucchetti at univpm.it
http://www.econ.univpm.it/lucchetti