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Re: st: sub-dataset by variable numbers


From   "Sebastian F. Büchte" <sfbuechte@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: sub-dataset by variable numbers
Date   Tue, 2 Oct 2007 13:51:21 +0200

Jianan

I do not think there is a direct command which will help you to
achieve what you would like. But, you could try the following:

unab vlist : _all
//keep 3rd to 6th variable from dataset in memory
keep `: word 3 of `vlist'' - `: word 6 of `vlist''

This will read all variable names into a local macro (vlist) and then
uses local extended functions to extract numbered elements from this
macro. For more information look at: -help unab- and -help
extended_fcn-

Regards
Sebastian

2007/10/2, Jian'an Luan <jal42@medschl.cam.ac.uk>:
> Dear Statalist
>
> I wonder if I can select a sub-dataset by variables without given
> variable names but using variable numbers, something like the command
> when select a sub-dataset by observations ".keep if _n>1001 & _n<2000".
>
> Any help will be appreciated.
>
> Jianan
>
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