[R] Problem with mutli-dimensional array

Berend Hasselman bhh at xs4all.nl
Tue Oct 2 17:20:46 CEST 2012

On 02-10-2012, at 16:20, Loukia Spineli <spineliloukia26 at gmail.com> wrote:

> I want to make a multi-dimensional array. To be specific I want to make the
> following array
> results<-array(0,dim=c(2,2,64,7))
> This is the code I have created but it gives no result due to the error
> "subscript out of bound".
> x<-rep(7,7)  # Missingness in intervention
> y<-rep(7,7) # Missingness in control
> arraynames<-list(Group=c("Success","Failure"),Outcome=c("Intervention","Control"),Trial=c("1":"7"))
> mat.stat<-array(c(9,16,10,15,66,12,44,23,102,88,66,104,277,60,247,119,23,43,20,41,201,162,122,
> 263,14,41,4,41),dim=c(2,2,7),dimnames=arraynames);mat.stat
> Nx<-rep(0,length(x))
> Ny<-rep(0,length(y))
> n<-(x+1)*(y+1)
> results<-array(0,dim=c(2,2,64,7))
> l<-1
> for(i in 1:length(x)){
> Nx[i] <- length(1:(x[i]+1))
> Ny[i] <- length(1:(y[i]+1))
> for(j in 1:(Nx[i])){
> for(k in 1:(Ny[i])){
> results[,,l,i]<-mat.stat[,,i]+matrix(c(c(0:x[i])[j],c(0:y[i])[k],-c(0:x[i])[j],
> -c(0:y[i])[k]),nrow=2,ncol=2,byrow=T)
> l<-l+1
> }
> }
> }
> results

If you had inserted this line


before the assignment to results[,,l,i] in the inner loop you could have quite easily seen what the problem is.
The counter l (letter el) keeps on increasing in your code and when it reaches 65 R will complain.

So at an appropriate place in the code you need to reset l to 1.
I suggest you move the assignment l<-1 to just before the  line with for( j in 1:Nx[i]) ...
Whether the results are what you desire is up to you to decide.

Please use some more whitespace  and do some indenting in your code. As presented it is unreadable.


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