RE: st: RE: Knowing how a variable was generated

[Louis Boakye-Yiadom <lby_kw@yahoo.co.uk>]

That's correct. I'm looking at a situation where the do-file is not available. Indeed, often you may have to work with a dataset for which you played no role in the generation of the variables. Thanks.

Louis


--- On Sun, 31/10/10, Nick Cox <n.j.cox@durham.ac.uk> wrote:

> Indeed. But Louis' question, and my
> answers, presuppose that was not done. 
> 
> Nick 
> n.j.cox@durham.ac.uk
> 
> 
> Michael McCulloch
> 
> Wouldn't it be sufficient to simple record the work in a
> do-file that documents the command:
>     gen B = (A*C) + D, or
>     gen B = A*(C + D)?
> 
> On Oct 31, 2010, at 9:46 AM, Nick Cox wrote:
> 
> > There are programs that enable users to record
> definitions of variables as they generate or replace them.
> See e.g. -labgen- from SSC and especially its references. 
> > 
> > More generally, if users employed variable labels or
> characteristics to record the definition of variables --
> then your problem is indeed soluble. 
> > 
> > I didn't imagine that's what you had in mind, as if
> you knew that definitions were stored that way it's hard to
> see why your question arises. 
>  
> Louis Boakye-Yiadom
>  
>  Nick, thanks for the reply. I was thinking that if it's
> possible for Stata to store information on the generation of
> the variable (at least in simple cases), it might be
> possible to have this feature in Stata.
>  
> Nick Cox
>  
> >> In general, no. How could there be? 
> >> 
> >> However, in simple cases for Y calculated somehow
> from X,
> >> looking at graphs of Y vs  X might give a
> clue. 
>  
> Louis Boakye-Yiadom
>  
> >> If some of the variables in a dataset were
> generated by a
> >> transformation or combination of some other
> variable(s) in
> >> the data, is it possible to know this without
> seeing the
> >> relevant log or do file? For example, consider a
> situation
> >> where the variables in the data include A, B, C,
> and D, and
> >> B was generated as follows:
> >> B = A*C + D
> >> Is there a command for determining how B was
> generated?
> 
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
> 


      

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/