RE: st: data management question

[Caroline Wilson <wilson_cj@hotmail.com>]

Apologies for the confusion - the variable "value" should have been called "Md_T".
Anyway, your solution worked perfectly - very many thanks!!!!

Caroline

----------------------------------------
> Date: Wed, 18 Sep 2013 18:33:19 -0400
> From: feenberg@nber.org
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st: data management question
>
>
>
> On Wed, 18 Sep 2013, Caroline Wilson wrote:
>
>> Hello,
>>
>>
>>
>> I’m wondering if someone can help with a data management
>> question.
>>
>>
>>
>> I’m trying to create a variable called “mean”, which, for a given
>> pat_ID, would be calculated by taking the mean of every other value of
>> “Md_T” in the same phy_ID EXCEPT for the current row.
>>
>
> I am a little unclear on what you are asking - Md_T isn't in the sample
> data you show, but you want the mean of it? So I won't use your variable
> names. Nevertheless, I think that the -egen- -total- function and a
> generate statement will get you what you want:
>
> by ID: egen sum=total(var)
> generate sumex= sum-var
> by ID: generate meanex = sumex/(_N-1)
>
> The total by ID gives the sum of var for each level of ID. Then we
> subtract the current level of var and divide by the number of observations
> in the ID group. (_N is the number of observations in the by group).
>
> Daniel Feenberg 		 	   		  
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