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st: Re: Re: RE: Multiple commands under "By varlist"?


From   "Michael Blasnik" <michael.blasnik@verizon.net>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: Re: Re: RE: Multiple commands under "By varlist"?
Date   Sat, 26 Jun 2004 10:22:14 -0400

I wonder if you are using an up-to-date -statsby- that included some
dramatic speed improvements for larger panel datasets like you are
sing.  -which statsby- shows the following for me:

*! version 2.0.5  13apr2004

The key speed improvement is from doing away with the -if- statements in the
group identification in the code and instead using -in-.  I find that
statsby with a regression on 1000 panels takes only slightly longer than
by...:regress.  Your finding of 15-20x longer indicates that you are most
likely using the older version.

Michael Blasnik
michael.blasnik@verizon.net


----- Original Message ----- 
From: "Subhankar Nayak" <nayak@bellsouth.net>
To: <statalist@hsphsun2.harvard.edu>
Sent: Saturday, June 26, 2004 9:57 AM
Subject: st: Re: RE: Multiple commands under "By varlist"?


> Thanks Nick,
>
> I tried the -statsby- command as Scott Merryman suggested and the -forval-
> command that you are suggesting. But both these take almost exactly the
same
> amount of time as the -while- looping command... (Given my program code,
> each simulation round is taking about 240-330 seconds, and I have got 1000
> simulation rounds, if not more).
>
> The -by- command is so much faster than the -while- command...
>
> If I compare
>
> by month: regress returns factor
>
> vs.
>
> local i = 1
> while i <= 1000 {
> regress returns factor if `i' == month
> local i = `i' + 1
> }
>
> I find that the -by- command is atleast 15-20 times faster than
the -while-
> loop.
> Given this, it would be really wonderful to be able to execute multiple
> commands under -by-...
> Some wishful thinking!
>


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