[R] Loop removal?

[kjetil halvorsen]

Look at the help for the cut() function, which does what you want, 
I think.

Kjetil Halvorsen

rijn at swi.psy.uva.nl wrote:
> 
> Dear all,
> 
> I've got a quite large dataframe (stor) with rows subject and rt (reaction
> time). I would like to split the reaction times per subject into 6 bins of
> equal size. Right now, I'm using the following code:
> 
> bindata <- function(rt) {
> 
>   bindata <- rep(-1,length(rt))
>   binwidth <- length(rt)/6
> 
>   bindata[order(rt)[(0*binwidth)+1:(1*binwidth)]] <- 1
>   bindata[order(rt)[(1*binwidth)+1:(2*binwidth)]] <- 2
>   bindata[order(rt)[(2*binwidth)+1:(3*binwidth)]] <- 3
>   bindata[order(rt)[(3*binwidth)+1:(4*binwidth)]] <- 4
>   bindata[order(rt)[(4*binwidth)+1:(5*binwidth)]] <- 5
>   bindata[order(rt)[(5*binwidth)+1:(6*binwidth)]] <- 6
> 
>   bindata
> }
> 
> for (i in unique(stor$subject)) {
>   stor[stor$subject == i,]$bin <- bindata(stor[stor$subject == i,]$rt)
> }
> 
> Although this code works fine, it does not "feel" very R'ish. Is there a
> more elegant solution for this, especially one that removes the for-loop?
> 
> Thanks,
>   Hedderik.
> 
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