This was the exchange Sergiy refers to.
I don't think that users can produce beasts like e(sample). My guess is
that StataCorp are using unpublicised hooks to do that.
Nick
--------------------------------------------------------------- 19 Dec
2003 ---
Nick Cox
See [U] 21.10 Saving results.
Zurab Sajaia
> I'm trying to find out how create some kind of function in
> stata. After any
> estimation command (regress for example)
> eret list gives functions: e(sample). If I write
> gen a=e(sample)
> and if we specified IF and/or IN options in regress, a=1
> for those in
> subsample and 0 otherwise. So, e(sample) is a function but
> how can I return other functions from my program?
------------------------------------------------------------------------
--------
Sergiy Radyakin
there was a question asked earlier on Fri, 19 Dec 2003 regarding
defining functions in Stata, but essentially no answer was given (or
none that I could find). Nick Cox pointed to the manual (I don't know
which edition, but "saving results" is now 18.10 of [U]). This part of
the manual does not describe the functions though.
Here are some observations:
Observation 1: some Stata commands return functions, e.g. -regress-
returns e(sample)
Observation 2: it is possible to get a list of defined functions by
reading extended macro function:
sysuse auto
regress p w
display `"`:e(functions)'"'
Observation 3: none of the official .ado files eshibits this feature
Observation 4: none of the user commands that I've seen uses this
feature.
If there is any new information available now, that was not available
in 2003 I would be glad to hear that.
Why do I need to know this? I am writing a command that automatically
processes the results saved in r() e() s() and at the very least I
need to know whether any user-defined command could, can or will be
able to save anything in the "functions" section.
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