Try this:
aggregate(example[c('x', 'y')], example[c('id', 'Year')], 'mean')
On Mon, Aug 9, 2010 at 11:46 AM, steven mosher <mosherste...@gmail.com>wrote:
> Assuming a data frame or matrix with two columns representing variable that
> you want to aggregate over.
> you want to calculate column means, by year, for each Id
>
>
>
>
> example<-data.frame(id=c(rep(12345,5),rep(54321,6),rep(45678,7)),Year=rep(seq(1900,1902,by=1),6),
> x=seq(1,18,by=1),y=seq(18,1,by=-1))
> example
> id Year x y
> 1 12345 1900 1 18
> 2 12345 1901 2 17
> 3 12345 1902 3 16
> 4 12345 1900 4 15
> 5 12345 1901 5 14
> 6 54321 1902 6 13
> 7 54321 1900 7 12
> 8 54321 1901 8 11
> 9 54321 1902 9 10
> 10 54321 1900 10 9
> 11 54321 1901 11 8
> 12 45678 1902 12 7
> 13 45678 1900 13 6
> 14 45678 1901 14 5
> 15 45678 1902 15 4
> 16 45678 1900 16 3
> 17 45678 1901 17 2
> 18 45678 1902 18 1
>
> result<-by(example[,3:4], example$id, by(example[,3:4],
> example$Year,colMeans, na.rm=T))
> Error in FUN(X[[1L]], ...) : could not find function "FUN
>
>
> desired result should look like:
> id Year meanx mean y
> 1 12345 1900 ... ...
> 2 12345 1901 ...
> 3 12345 1902 ...
> 4 54321 1900
> 5 54321 1901
> 6 54321 1902
> 7 45678 1900
> 8 45678 1901
> 9 45678 1902
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
