[R] multiple tapply

[Chuck Cleland]

On 8/7/2008 7:01 AM, glaporta wrote:
> Hi folk,
> I tried this and it works just perfectly
> tapply(iris[,1],iris[5],mean)
> but, how to obtain a single table from multiple variables? 
> In tapply x is an atomic object so this code doesn't work 
> tapply(iris[,1:4],iris[5],mean)
> 
> Thanx and great summer holidays
> Gianandrea 

   And a third approach:

 > sapply(split(iris[,1:4], iris$Species), colMeans)
              setosa versicolor virginica
Sepal.Length  5.006      5.936     6.588
Sepal.Width   3.428      2.770     2.974
Petal.Length  1.462      4.260     5.552
Petal.Width   0.246      1.326     2.026

-- 
Chuck Cleland, Ph.D.
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