[R] mapping array

[Gregory Ryslik]

  Hi,

Suppose I have array A with 100 elements all filled in with "N/A". Array 
B has 25 elements with actual values. Lastly, I have array C that 
provides a map of where to put the elements from array A into array B. 
Thus C would say put element 1 from B into element 3 from array A.

I realize I can do this with a for loop. However, because I'm doing a 
random forest with this, I'd like to avoid a for loop because it would 
take significantly more time.

Thanks,
Greg