[R] create index for tapply or by

[Rui Barradas]

Hello,

Try using ?cut


y2 <- cut(x, breaks)
by(x, y2, sum)


Hope this helps,

Rui Barradas

Em 27-06-2013 09:24, Witold E Wolski escreveu:
> Is there a build in function to create an index for tapply or by given a
> a numeric vector x an a vector of breaks?
>
> What I want to do is:
>
> x <- 1:100
> breaks <- c(0,10,20,50,99,110)
>
> y <- rep(0,length(x))
> for(i in 2:length(breaks)){
>    y[which(x>breaks[i-1] & x <= breaks[i])] <- i
> }
>
> by(x,y,sum)
>
> but I find the code especially th for loop unneRving.
>
>