r - How to change order of array dimensions

Question

How do I reorder the dimensions of an n dimensional array. For example, if I have a three dimensional array of sales data, where the first dimension represents the Date, the second dimension is the Store, and the third dimension is Department. How do I transform the array so that the first dimension is Store, the second is Department, and the third is Date. This is just an example. I am hoping for a general solution.

Answer 1

The function for doing that is aperm, from the base package. It is a generalization of the transpose t() function to multidimensional arrays. For your example, you would call it as follows:

new.data <- aperm(old.data, c(2,3,1))