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

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

Thanks for this and all the previous comments.

Louis

--- On Mon, 1/11/10, Richard Goldstein <richgold@ix.netcom.com> wrote:

> From: Richard Goldstein <richgold@ix.netcom.com>
> Subject: Re: st: RE: Knowing how a variable was generated
> To: statalist@hsphsun2.harvard.edu
> Date: Monday, 1 November, 2010, 13:46
> note that there is a program for
> this, -defv-; use -findit-
> 
> however, this program does not work with -egen- and does
> not work with
> -by- (and does not always work with Stata 11 either)
> 
> Rich
> 
> On 11/1/10 5:43 AM, Ulrich Kohler wrote:
> > I principal it is also possible to store this
> information as note: 
> > 
> > . sysuse auto
> > . gen x = weight - 1
> > . note x: gen x = weight - 1
> > 
> > . replace x = weight +1
> > . note x : replace x = weight + 1
> > 
> > . note x
> > 
> > Clearly it is possible to write programms (i.e.
> -gennote- and
> > -replacenote-) that do this automatically. The
> question however arise
> > why someone who is not willing to give away his
> do-files should use
> > these programs when creating a data set ...
> > 
> > Uli
> > 
> > 
> > Am Sonntag, den 31.10.2010, 17:41 +0000 schrieb Louis
> Boakye-Yiadom:
> >> 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?
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