st: Dropping observations in relation to mean and standarddeviation

[Friederike Ballaire <fhornber@mail.uni-mannheim.de>]

Hi,
I tested 144 people and now I need to drop observation that are more
than three standarddeviations away from the mean of two variables for
one subject.

So far I calculated the standard deviation and the mean of v1 and v2
if subject number = 10011.

my syntax lokks like this:
preserve
stack v1 v2 if subject ==10011, into(v3) clear
tabstat v3, statistics( mean sd ) columns(variables)
restore

Now I want to delete all data that is more than three standard
deviations away from the mean.

Is there a special command for that?
Otherwise I would just calculate the mean and standarddeviation for
every subject and then calculate three standard deviations away from
the mean and use the drop command.

Thanks for your help!
Friederike Ballaire
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