[R] weighted mean by week

[Dimitri Liakhovitski]

David, thanks a lot!
I tried x[-1] myself but forgot to delete 'group' from the keyby
statement - this explains why it did not work for me.
This is amazing - just 2 lines instead of my many-many.
Great learning!
Dimitri


On Tue, Jul 17, 2012 at 10:49 PM, David Freedman <dxf1 at cdc.gov> wrote:
> Honestly, I wasn't sure what you wanted to do with 'group'.  Here it is with
> the 'group' variable deleted
>
> library(data.table)
> dt=data.table(x[,-1])
> dt[,lapply(.SD, function(x)weighted.mean(x,myweight)), keyby='myweek']
>
>
>
>
> --
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> Sent from the R help mailing list archive at Nabble.com.
>
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-- 
Dimitri Liakhovitski
marketfusionanalytics.com