Message-ID: <4B0A4486.1060202@global-analytics.com>
Date: 2009-11-23T08:15:02Z
From: utkarshsinghal
Subject: FUN argument to return a vector in aggregate function
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.
Is there any other function same as aggregate which allow FUN argument
to return vector.
Regards
Utkarsh