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Re: st: how to add 23 in each row of a variable


From   Martin Weiss <mw.stlist@googlemail.com>
To   <statalist@hsphsun2.harvard.edu>
Subject   Re: st: how to add 23 in each row of a variable
Date   Mon, 15 Sep 2008 20:19:50 +0200

I see braod agreement on the solution. This thread is a tough reminder, though, of the difficulties that can sometimes seem insurmountable for beginners in Stata. Having had a distraught student walk into my office a couple of days ago with the exact same problem, I think it is extremely important to emphasize that Stata does not exactly "push" subscripting as a solution to data management problems. I would have trouble recalling a single instance where subscripting has proved necessary for me in Stata...

Martin Weiss
_______________________
----- Original Message ----- From: "Eva Poen" <eva.poen@gmail.com>
To: <statalist@hsphsun2.harvard.edu>
Sent: Monday, September 15, 2008 8:10 PM
Subject: Re: st: how to add 23 in each row of a variable



Fabian,

er, no need for a loop. May

replace number = number + 23

be what you want?

The code for your (unnecessary!) loop as a few mistakes which I am
going to correct anyway.
If you use -while-, you have to increment your counter macro inside the loop:
local i 1
while `i' < 100 {
....
local ++i
}

Else you have an infinite loop, because the initial condition is
always true. -foreach- and -forvalues- are usually much better
choices, and run faster, I believe.

Your condition -while `i' < _N- leaves out the last observation. Next,
number[i] should read number[`i']. _However_, none of this is
necessary! Use -generate- and -replace-.

Eva


2008/9/15 Fabian Brenner <Fabian.Brenner@gmx.de>:

Hello,

how can I tell Stata to add 23 in each row of a variable in the dataset?

I do not know what I am doing wrong because it does not work like this:

local i=1
while `i'<_N {
 2. replace number[i]= number[`i'] + 23
 3. }

Thanks for your help.
Fabian

P.S. Thanks a lot to Neil for the help.

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