[R] Summary of data.frame according to colnames and grouping factor

[baptiste auguie]

Hi,

You could use the reshape package:


> d$e <- e
>
> recast(d, variable~e, fun=sum)


The doBy package is another option.

baptiste

On 8 Mar 2009, at 17:14, soeren.vogel at eawag.ch wrote:

> A dataframe holds 3 vars, each checked true or false (1, 0). Another
> var holds the grouping, r and s:
>
> ### start:example
> set.seed(20)
> d <- data.frame(sample(c(0, 1), 20, replace=T), sample(c(0, 1), 20,
> replace=T), sample(c(0, 1), 20, replace=T))
> names(d) <- c("A", "B", "C")
> e <- rep(c("r", "s"), 10)
> ### end:example
>
> How do I get the count of "1's" (or any other function) applied over
> each var according to the grouping? That is:
>
> Desired output table:
>
>        A      B      C
> r  count  count  count
> s    ...    ...    ...
>
> or likewise transposed. I'd like to use the table for textual display
> and/or barplot creation.
>
> Thx, Sören
>
> --
> Sören Vogel, PhD-Student, Eawag, Dept. SIAM
> http://www.eawag.ch, http://sozmod.eawag.ch
>
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_____________________________

Baptiste Auguié

School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK

Phone: +44 1392 264187

http://newton.ex.ac.uk/research/emag