Re: st: Drop subjects from a panel

[Klaus Pforr <kpforr@googlemail.com>]

Dear Ayman,

It depends on what you want to do. Do you want to drop cases with a 
specific combination of a covariate and the process time? Or do you want 
to drop a specific element in the sequence of measurements for each 
panel group? Is the "2" from <time==2> different for each panel group?

The simple answer I gave you does the first for a specific static 
combination (I guess you knew that already). Anything else depends on 
what you want to do.

Klaus


Am 08.02.2012 22:28, schrieb Ayman Farahat:
> Thanks Klauss;
>
> One question : Wouldnt this just remove the observation at time==2 while leaving the observations at different times?
> Ayman
>
>
>
> ----- Original Message -----
> From: Klaus Pforr<kpforr@googlemail.com>
> To: statalist@hsphsun2.harvard.edu
> Cc:
> Sent: Wednesday, February 8, 2012 12:52 PM
> Subject: Re: st: Drop subjects from a panel
>
> <>
>
> Hello Ayman,
>
> try
> <drop if covariate==0&  time==2>
>
> best
>
> Klaus
>
> Am 08.02.2012 21:36, schrieb Ayman Farahat:
> > Hello ;
> >
> >     I have a panel data. I would like to remove all subjects that had a certain co-variate at a specific time.
> >
> > For example, drop all subjects that had a covariate==0 for time==2.
> > Any help greatly appreciated.
> >
> > Thanks
> > Ayman
> >
> >
> > *
> > *   For searches and help try:
> > *  http://www.stata.com/help.cgi?search
> > *   http://www.stata.com/support/statalist/faq
> > *   http://www.ats.ucla.edu/stat/stata/


--
__________________________________

Klaus Pforr
MZES AB - A
Universität Mannheim
D - 68131 Mannheim
Tel:  +49-621-181 2797
fax:  +49-621-181 2803
URL:  http://www.mzes.uni-mannheim.de

Besucheranschrift: A5, Raum A309
__________________________________

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