st: Re: help creating a unique identifier

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

A similar question was recently asked and FAQ certainly addresses the unique 
identifier, but here are some answers:

egen SeqId=group(id_dom)

or

sort id_dom age
gen SeqId=sum(id_dom!=id_dom[_n-1])

for your second question, if there are no missing values on age, then this 
works:

bysort id_dom (age): gen byte hasover15=age[_N]>=15

otherwise, the easiest approach may be:

egen maxage=max(age),by(id_dom)
gen byte hasover15=maxage>15 if maxage<.


There is no need for collapse or merge and I can't see any reason why you 
would think so.

Michael Blasnik
michael.blasnik@verizon.net

----- Original Message ----- 
From: "Joao Pedro Wagner de Azevedo" <jazevedo@provide.com.br>
To: <statalist@hsphsun2.harvard.edu>
Sent: Thursday, March 17, 2005 11:42 AM
Subject: st: help creating a unique identifier



> Hello,
>
> I have a dataset with the variable id_dom (numeric) which s a unique
> identifier of households and the variable age (see extract below). I would
> like to create a couple of new variable and I would sincerely appreciate 
> if
> anyone on the list give me a hand.
>
> First, I would like to create a sequential unique identifier such as
> variable SeqID. Second, I would like to create a variable which would flag
> all those households with at least on adult (age>=15).
>
> Initially I would like to avoid having to use collapse and merge (given 
> the
> size of my dataset), and I have been trying to use command such as bysort,
> _n and _N.
>
> Any help will be much appreciated.
>
> Cheers,
>
> JP
>
>
> id_dom age SeqID
> 9211001200001 5 1
> 9211001200001 10 1
> 9211001200001 15 1
> 9211001200001 20 1
> 9211001200001 25 1
> 9211001200002 5 2
> 9211001200002 10 2
> 9211001200002 15 2
> 9211001200002 20 2
> 9211001200002 25 2
> 9211001200003 4 3
> 9211001200003 8 3
> 9211001200003 12 3
> 9211001200003 16 3
> 9211002100002 3 4
> 9211002100002 6 4
> 9211002100002 9 4
> 9211002500004 7 5
> 9211002500004 14 5
> 9211002500004 21 5
> 9211002500004 28 5
> 9211002500004 35 5
> 9211002500004 42 5
> 9211002500004 49 5
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