Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: RE: Creating missing data


From   "Nick Cox" <n.j.cox@durham.ac.uk>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: RE: Creating missing data
Date   Thu, 4 Nov 2004 01:18:13 -0000

Suppose your identifiers run 1, 2, ... . If this isn't true, 

. egen id = group(whateverisyourid) 

will make it so. 

Now, if I understand you correctly, you want to 

. bysort id (entrytime): 
	replace somevar = . if _n == 1 & mod(id,5) == 0 

Nick 
n.j.cox@durham.ac.uk 

celdjt@umich.edu
 
> My 
> question is about making an adjustment to the surrogate data set. The 
> surrogate data set contains about 3500 cases, some of which 
> have just one 
> record per case, and others have multiple records. Each record has a 
> variable recording an entering time and an exit time for that record. 
> Hence, single record cases have one entry time and one exit 
> time; multiple 
> record cases have multiple entry and multiple exit times. I 
> would like to 
> convert the first entry time for every fifth multiple-record 
> case in this 
> data set into a missing value. Are there any suggestions for 
> how this might be done. 

*
*   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/



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