[R] about a series of arrays

[Uwe Ligges]

Z P wrote:

> Dear all,
> 
> I now have a sequence of n<-3:21, for each i, I define an array of 
> dimension
> array((1/2)^i,c(rep(2,i))), I must update the (i+1)-th array with a loop 
> according to the i-th array, How can I store all the previous arrays 
> (the marginal parts of the (i+1)-th array will not equal to the i-th 
> array)? It is in an iteration from 3 to 21, I later will need all the 
> arrays. If I define 19 different variables, I still can not assign 
> arrays to them in the iteration. What can I do? Thanks.
> 
> Regards,
> 
> Zhen


Use a list as in:

  Alist <- vector(21, mode="list")
  n <- 3:21
  for(i in n){
     Alist[[i]] <- array(1/2^i, rep(2,i))
  }

with Alist[[3]] as the first non-NULL element, or:

  Alist <- lapply(3:21, function(i) array(1/2^i, rep(2,i)))

with Alist[[1]] as the first non-NULL element


Uwe Ligges

PS: Why do you ask R-help in CC, and other people as the main addresses?