Neuroimage software - scientific computing and visualization

So are you saying that if you have an array like:
  a = ['d', 'b', 'a', 'c', 'e']
You would like to get something like:
  a.sort_index #=> [2, 1, 3, 0, 4]

If that's the case, then I'm sure it's doable. No built-in
method that I'm
aware of, but you could easily create one.

For example:

class Array
  def sort_index
    (0...size).sort_by {|i| self[i]}

%w{d b a c e}.sort_index
=> [2, 1, 3, 0, 4]