Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Missing observations


From   Nick Cox <njcoxstata@gmail.com>
To   "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu>
Subject   Re: st: Missing observations
Date   Thu, 20 Jun 2013 11:32:55 +0100

-drop- as used here drops entire observations (outside Stata
observations are known as rows, cases, records). You seem to be under
the impression that there is an operation

drop missing values

that is somehow different from

-drop- observations

but I don't know what that would look like.

In your example if -var2- has only 169 non-missing values (_not_
observations) then

drop if missing(var2)

will leave precisely 169 observations. I don't understand how that is
a surprise or what else you want.

Nick
njcoxstata@gmail.com


On 20 June 2013 11:17, Csaba Kertai <csaba.kertai@hotmail.co.uk> wrote:

> I need a bit of help with dropping missing observations. If I use 'drop if missing(var)' or drop if 'var'==. etc. many other observations are dropped as well. More precisely, var1 has 1125 observations and var2 has 169 observations. I want to drop missing observations for var2 but if I use drop if var2==. then this will keep only 169 observations for each variable. I only want to drop values that are missing.

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index