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Re: st: Observation variable transformation


From   Philip Ryan <philip.ryan@adelaide.edu.au>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Observation variable transformation
Date   Sun, 11 Sep 2005 09:23:54 +0930

Given X has contiguous increasing integer values from 1 to _N, the -egen-
function -seq()- will also accomplish this.

egen X1 = seq(), block(10)

see -help egen-

[I do not think you mean "successive observations of 10 *variables*. I think
you mean "successive observations (on a single variable) in blocks in 10".
Correct me if I'm wrong, but confusion over variable/observation terminology
can ambush both the poser of and the responder to a question.]

Phil



Quoting Svend Juul <SJ@SOCI.AU.DK>:

> Kelly wrote:
>
> I have created an observation variable X (e.g. gen X=_n) for a large data
> set. How can I create a new variable that is unique for successive
> observations of 10 variables (i.e. i want this variable to be equal to 1 in
> obs 1-10, 2 in 11-20, and so forth)?
> ----
>
> Try this:
>     clear
>     set obs 50
>     gen X=_n
>     gen X1 = int((X+9.5)/10)
>     list
>
> I added 9.5, not 9, to prevent rounding errors.
>
> Hope this helps.
>
> Svend
>
>
>
> ________________________________________________________
>
> Svend Juul
> Institut for Folkesundhed, Afdeling for Epidemiologi
> (Institute of Public Health, Department of Epidemiology)
> Vennelyst Boulevard 6
> DK-8000 Aarhus C,  Denmark
> Phone, work:  +45 8942 6090
> Phone, home:  +45 8693 7796
> Fax:          +45 8613 1580
> E-mail:       sj@soci.au.dk
> _________________________________________________________
>
> *
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>


-- 
Philip Ryan
Associate Professor
Department of Public Health

Associate Dean (IT)
Faculty of Health Sciences

Head, Data Management and Analysis Centre
Department of Public Health and Department of General Practice

University of Adelaide
5005 South Australia
AUSTRALIA
CRICOS Provider Number 00123M
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