[R] Apply: Output matrix orientation

[David Winsemius]

On May 27, 2010, at 7:24 AM, Johannes Graumann wrote:

> Hi,
>
> Why is the result of below "apply" call rotated with respect to the  
> input
> and how to remedy this?

Because the processing you requested is with respect to rows and the  
construction of matrices is by default by columns.

?t


>
> Thanks, Joh
>
> .ZScore <- function(input){
>  #cat(input,"\n")
>  z <- (input - mean(input))/sd(input)
>  return(z)
> }
>
> apply(data.frame(x1=c(1,2,3,4,5),x2=c(2,3,4,5,6),x3=c(3,4,5,6,7)), 
> 1,.ZScore)

David Winsemius, MD
West Hartford, CT