# st: SV: Calculate the mean of y if there are many similar x

 From Pär-Ola Bendahl To Subject st: SV: Calculate the mean of y if there are many similar x Date Fri, 18 Mar 2005 13:33:22 +0100

```Hi,

bysort x:egen y_mean=mean(y)
sort x
drop if x==x[_n-1]

will do the job,

Pär-Ola Bendahl

> -----Ursprungligt meddelande-----
> Från: owner-statalist@hsphsun2.harvard.edu
> [mailto:owner-statalist@hsphsun2.harvard.edu] För Eik Leong Swee
> Skickat: den 18 mars 2005 05:45
> Till: statalist@hsphsun2.harvard.edu
> Ämne: st: Calculate the mean of y if there are many similar x
>
>
> Hello. I have a problem here trying to sort my data. I have 2
> variables y and x. Each one is of length 15000. However, y is
> unique but x is not i.e. for some values of y, there are more
> than one x. Specifically, there are 3573 unique values of x.
> I wish to take the mean of y for those x's that are the same,
> so that I end up only with a unique set of 3573 (y,x). I can
> either manually compute the mean 3573 times, or hopefully
> someone out there knows a command I can use. THANKS A LOT in advance!
>
>
>
>
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