Re: st: storing values from within "by varname :" command

["Michael Blasnik" <michael.blasnik@verizon.net>]

This type of code can be useful in some circumstances, but I think you 
should first look at -statsby- which basically does the same thing for 
almost any Stata command that returns results, only faster and in a single 
line.

Michael Blasnik

----- Original Message ----- 
From: "David Elliott" <dcelliott@gmail.com>
To: <statalist@hsphsun2.harvard.edu>
Sent: Sunday, October 22, 2006 10:19 AM
Subject: Re: st: storing values from within "by varname :" command



> Andrey
>
> Unless the command you are iterating for the by variables allows some
> way to save values, or if you actually add that feature to the ado you
> are calling, I don't believe what you want is possible within the
> context of the by command.
>
> There is an alternative, however:
>
> ===============================
> // This assumes variables region and group are numeric
> // If they are strings the commands postfile and post and the ifcmd must
> // be altered accordingly
>
> tempname h
> postfile `h' region_level group_level count using mycounts, replace
>
> levelsof region, local(l_region)
> levelsof group, local(l_group)
>
> foreach region_level of local l_region {
> foreach group_level of local l_group {
> count if region==`region_level' & group==`group_level'
> // count is returned in r(N) so
> local count=`r(N)'
> post `h' (`region_level') (`group_level') (`count')
> }
> }
>
> postclose `h'
> use mycounts, clear
> browse
>
> =============================
>
> With a little work, this could be adoed to accept a more general case
> of passthru commands and capture the postfile output, even
> transferring variable and value labels to the new file.
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