|
|  |
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]
Re: st: combining two variables
Why would one need "if missing(var1, var2)" ?
gen newvar=max(var1,var2)
produces the same result, unless:
Ambiguity exists, since Paswel Phiri Marenya wanted to "combine the
variables in such a way that the data from one variable can replace the
missing values from the other". It is as above if the situation of both
non-missings is impossible (say, by way the variables are created). If,
however, it is possible, then NGC's solution will yield new missings, which
contradicts "data ... replace the missings". So because of the way the
question is formulated, and because it's not known if both variables may
have non-missings, you may wish to consider this code:
gen newvar=var1
replace newvar=var2 if var1==.
Regards, Sergiy
----- Original Message -----
From: "Nick Cox" <[email protected]>
To: <[email protected]>
Sent: Wednesday, March 07, 2007 6:14 PM
Subject: RE: st: combining two variables
Some very complicated solutions here!
Consider:
gen newvar = max(var1, var2) if missing(var1, var2)
Logic:
If just one of var1 or var2 is missing,
then -missing()- will return true.
In that case, max(var1, var2) will
return the non-missing value in question.
If both are missing, then you get missing returned,
but that is fair enough.
If neither is missing, missing is returned.
Nick
[email protected]
Paswel Phiri Marenya
What to me is easier is something like:
gen var3 = var2
then replace var3=var1 in 4/5 and so on...although with a
long data set it
may be tedious perhaps.
regrads
PPm
> Thank you to everyone who answered my last question on
> creating a variable corresponding to the row number.
>
> Now I have a question about combining the data from two
> variables (in the same data set) into one variable. I want to
> combine the variables in such a way that the data from one
> variable can replace the missing values from the other. I have
> created an example of what I am looking for below:
>
>
> Have: Want:
> var1 var2 newvar
> . 2 2
> . 8 8
> . 0 0
> 7 . 7
> 3 . 3
> . . .
>
> Any thoughts on how to do this?
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
