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st: Creating a mean of x entries in variable1 if there are at least x entries in variable1 by person id
From
Nicholas Winters <[email protected]>
To
"[email protected]" <[email protected]>
Subject
st: Creating a mean of x entries in variable1 if there are at least x entries in variable1 by person id
Date
Wed, 9 Oct 2013 00:07:21 +0000
Sorry for the complicated subject, this is what my data looks like:
person id exposure year
1 3 1
1 3 2
1 4 3
1 3 4
1 3 5
2 4 1
2 4 2
2 3 3
2 4 4
3 1 1
3 2 2
3 3 3
3 2 4
I want to take an average of 'exposure' if there are at least, say, 3 entries in 'year' per person id. So I want to end up with a new variable, mean_exposure, that looks like this:
person id mean_exposure
1 3
2 4
3 3
4 2
I've tried by person id: egen mean_exposure=mean(exposure) if _____________
but I want the mean of ALL values in exposure only if 'year' has at least x number of observations
please help, I'm stumped...?
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