# Re: st: Looping question

 From Maarten buis To statalist@hsphsun2.harvard.edu Subject Re: st: Looping question Date Sat, 18 Mar 2006 18:38:59 +0000 (GMT)

```Carter:
The trick is a combination of -reshape- and -merge-. See example.
HTH,
Maarten

*---------------begin example-------------
drop _all
tempfile a
input frnd delinq
99   2
88   3
77   5
66   2
55   6
44   8
end
sort frnd
save `a', replace

drop _all
input aid frnd1 frnd2 frnd3 frnd4
99   66    77   .     .
88   77    99   .     .
77   55    44   99
66   88    99   44   77
55   44    .    .    .
44   66    .    .    .
end

reshape long frnd, i(aid)
drop if frnd ==.
sort frnd
merge frnd using `a'
drop if _merge == 2 /*remove people who are nobodys friend*/
drop _merge
reshape wide frnd delinq, i(aid) j(_j)
list
*---------------------end example-----------------------

--- Carter Rees <carterrees@gmail.com> wrote:
> I am working with a data set in which cases are students each of which has a
> unique identifier aid.  Also, for each student I have a delinquency variable
> (delinq) which is a count of the number of delinquent acts they have
> committed over the past 12 months.  Each student has nominated up to 10
> friends which are represented by the variable vector frnd1-frnd10.  The
> values of frnd1-frnd10 are the aid's of each of the nominated friends.  What
> I would like to do is create a variable vector fr1del-fr10del which takes on
> the delinquency value for each of the nominated friends.

> aid delinq frnd1 frnd2 frnd3 frnd4 frnd5 ...
> 99   2       66    77
> 88   3       77    99
> 77   5       55    44   99
> 66   2       88    99   44   77
> 55   6       44
> 44   8       66
>

-----------------------------------------
between 1/2/2006 and 31/3/2006 I will be
visiting the UCLA, during this time the
best way to reach me is by email

Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands

Buitenveldertselaan 3 (Metropolitan), room Z214

+31 20 5986715

http://home.fsw.vu.nl/m.buis/
-----------------------------------------

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