Try this:
> t(apply(x, 1, function(x) (x == max(x)) - (x == min(x))))
[,1] [,2] [,3]
[1,] -1 0 1
[2,] 1 -1 0
[3,] 1 0 -1
You can avoid the transpose using plyr:
> library(plyr)
> aaply(x, 1, function(x) (x == max(x)) - (x == min(x)))
Var1 1 2 3
1 -1 0 1
2 1 -1 0
3 1 0 -1
On Wed, Jan 20, 2010 at 11:57 AM, <murali.me...@fortisinvestments.com> wrote:
> Folks,
>
> I've got a matrix x as follows:
>
>> x <- matrix(c(1,2,3,5,3,4,3,2,1), ncol = 3, byrow = TRUE)
>> x
> [,1] [,2] [,3]
> [1,] 1 2 3
> [2,] 5 3 4
> [3,] 3 2 1
>
>
> In each row of x, I want to replace the minimum value by -1, the maximum
> value by +1 and all other values by 0.
>
> So in the above case I want to end up as follows:
>
> [,1] [,2] [,3]
> [1,] -1 0 1
> [2,] 1 -1 0
> [3,] 1 0 -1
>
> I tried the following, which seems to work:
>
>> t(apply(x, 1, function(y) {z <- numeric(NROW(y)); z[which.min(y)] <-
> -1; z[which.max(y)]<- 1; z}))
>
> Is there a neater way to do this?
>
> Thanks,
>
> Murali
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
