bysort subject (period) : gen accumcon=sum(con)
also worked! :-)
Thank you very much!
Martin Weiss schrieb:
<>
Try Nick`s http://www.stata-journal.com/sjpdf.html?articlenum=pr0004 for
further explanations...
*************
clear*
set obs 10
gen byte subject=_n
expand 10
bys subject: gen byte time=_n
gen con=int(runiform()*20)
bys subject (time): gen accumcon=sum(con)
l, sepby(subject) noo
*************
HTH
Martin
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[mailto:[email protected]] Im Auftrag von
[email protected]
Gesendet: Donnerstag, 14. Januar 2010 17:49
An: [email protected]
Betreff: st: Calculating a (changing) accumulative sum
I have 20 "period"s (i.e., 20 rows) of data for each "subject" i. For
each subject i, I would like stata to calculate the accumulative sum of
the variable "con" in a new variable "accumcon" in the following way:
In period 1: accumcon = con[1]. In period 2: accumcon = con[1]+con[2]
In period 3: accumcon = con[1]+con[2]+con[3] and so on, for each
subject, from period 1 until period 20.
Thank you for your help.
--
Dr. Özgür Gürerk
Lehrstuhl für Mikroökonomie & Laboratorium für experimentelle Wirtschaftsforschung
(Microeconomics & Laboratory for Experimental Economics)
Universität Erfurt, Nordhäuser Str. 63, D-99089 Erfurt
Tel: +49 361 7374561
Fax: +49 361 7374569
www.uni-erfurt.de/elab
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