st: Re: keep

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

..
Here's one way -- put a list of all variables in a local macro and your target 
list in another and use extended macro function to find their intersection:

unab allvars: _all
local include "v1 v2 v3"
local keepvars: list vars & include
keep `keepvars'

You could also use a foreach loop to construct the set the keep or drop.

Michael Blasnik

----- Original Message ----- 
From: "Erik Bihagen" <erik.bihagen@sofi.su.se>
To: <statalist@hsphsun2.harvard.edu>
Sent: Monday, September 10, 2007 7:09 AM
Subject: st: keep



> Hi Statalisters,
>
> Is there a way to let the keep command do the following?
> I want to keep, let's say, three variables v1 v2 v3 before saving data, but 
> all these three variables do not exist in all data sets for which I want to 
> run the command (I want to do this with a loop using many data sets and I use 
> global to define the variables).
>
> I could drop variables instead using "capture drop v4" etc, but that would 
> become a very long do file.
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