Odp: FUN argument to return a vector in aggregate function
Hi r-help-bounces at r-project.org napsal dne 23.11.2009 09:15:02:
Hi All, I am currently doing the following to compute summary statistics of aggregated data: a = aggregate(warpbreaks$breaks, warpbreaks[,-1], mean) b = aggregate(warpbreaks$breaks, warpbreaks[,-1], sum) c = aggregate(warpbreaks$breaks, warpbreaks[,-1], length) ans = cbind(a, b[,3], c[,3]) This seems unnecessarily complex to me so I tried
> aggregate(warpbreaks$breaks, warpbreaks[,-1], function(z)
c(mean(z),sum(z),length(z))) but aggregate doesn't allow FUN argument to return a vector. I tried "by", "tapply" and several other functions as well but the output needed further modifications to get the same format as "ans"
above.
It is work for sapply/split.
sapply(split(warpbreaks$breaks, warpbreaks[,-1]), function(x) c(mean(x),
sum(x), length(x)))
A.L B.L A.M B.M A.H B.H
[1,] 44.55556 28.22222 24 28.77778 24.55556 18.77778
[2,] 401.00000 254.00000 216 259.00000 221.00000 169.00000
[3,] 9.00000 9.00000 9 9.00000 9.00000 9.00000
Regards Petr
Is there any other function same as aggregate which allow FUN argument to return vector. Regards Utkarsh
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