[R] Question about manipulating quartiles
ggrothendieck at myway.com
Sat Jul 31 09:36:50 CEST 2004
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by(iris, quantcut(iris[,1]), function(x) sum(x[,1]/x[,2]))
From: Ajay Shah <ajayshah at mayin.org>
I know the `quantcut' function in the gregmisc package, and using it,
I'm able to use functions like aggregate to compute the mean or sd()
in each quartile.
What if I have a data frame containing x and y, and I want to make
quartiles by x, but then compute sum x / sum y in each quartile?
How does one persuade aggregate to do this?
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