# Re: st: addition of variables in Stata 11

 From Ekaterina Hertog To "statalist@hsphsun2.harvard.edu" Subject Re: st: addition of variables in Stata 11 Date Sun, 25 Oct 2009 19:07:09 +0000

```Dear Nick, Martin and John,
```
Thank you very much for the advice! Nick's and Martin's clarifications on the impossibility of using the -by option is taken.
```Sincerely yours,
Ekaterina

Nick Cox wrote:
```
Please note: 1. This is the same function as -egen, rowtotal()- named in my earlier post. -rsum()- was renamed -rowtotal()- in Stata 9. 2. However, -by()- is irrelevant to row-wise operations and is in any case not supported (i.e. illegal) with this function. Nick n.j.cox@durham.ac.uk
```John Ataguba

I suppose these are variables created in rows.  You can try:

egen newvar = rsum(citotal*)

Note that you can also combine this with the by option if you want to restrict to a certain group or so...

Ekaterina Hertog <ekaterina.hertog@sociology.ox.ac.uk>

I have a set of variables which denote population by age group in a
location a given individual lives in my dataset and I want to add them
up to total population in a location where each individual lives.
The names of the variables I have look as follows:
citotal1519 (meaning total population of 15 to 19 year olds in the city)
citotal2024 (meaning total population of 20 to 24 year olds in the city)
citotal2529 (meaning total population of 25 to 29 year olds in the city)
…
citotal7074 (meaning total population of 70 to 74 year olds in the city)

I was wondering if it might be possible to somehow ask Stata to add all

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```

--
Ekaterina Hertog (née Korobtseva)
Career Development Fellow
Department of Sociology and Nissan Institute of Japanese Studies
University of Oxford

Oxford
OX2 6NA
United Kingdom

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