If you type out the full command, then Stata will re-do the analysis.
Replaying results will prove to be much faster than re-estimating the
command, especially when you're working with large datasets or complex
estimation commands.
Michael Blasnik
[email protected]
----- Original Message -----
From: "Richard Williams" <[email protected]>
To: <[email protected]>
Sent: Saturday, December 13, 2003 7:29 PM
Subject: st: Is Stata smart enough to avoid unnecessary repetition?
> Is Stata smart enough to know when it already has the necessary
information
> calculated for an estimation command? For example, if I do
>
> regress y x1 x2 x3
> regress y x1 x2 x3
>
> will stata redo the regression or will it know that it has already done it
> and just replay the results? Or, less obviously, if you do something like
>
> regress y x1 x2 x3
> pcorr y x1 x2 x3
>
> the -pcorr- command will quietly regress y x1 x2 x3. Will Stata do that
> regression anew or does it know it doesn't need to bother?
>
> If Stata is smart enough to avoid repetition, will it also be smart enough
> to know that it must start from scratch if the data have been edited or
> changed?
>
> Put another way, does it make any difference whether I just replay results
> (e.g. type -regress- with no arguments) as opposed to repeating the
> original complete command?
>
> I've been using Stata with small data sets and it seems extremely
> fast. But, I may start using it with some enormous data sets, and I'm
also
> starting to write some ado files, and I'm wondering whether I have to
worry
> about how efficient my commands are or if Stata will choose the optimal
> strategy.
>
>
>
> -------------------------------------------
> Richard Williams, Associate Professor
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