Populate columns of matrix without for loop using input from a vector of intergers

I am looking for a way to generate a target matrix for the neural network toolbox using labeled data where each class is represented in an vector of integers.

Example:

X =
 [0
  2
  1 
  2
  3]

I need this in the form

X = [ 1 0 0 0
      0 0 1 0
      0 1 0 0
      0 0 1 0 
      0 0 0 1]

Is it possible to do this without a loop?

Thanks

Answer 1

[José-Luis]

   X=[0, 2, 1, 2,  3];
   numCols = max(X) + 1;
   result = zeros(numel(X),numCols);
   idx = sub2ind(size(result),1:numel(X),X+1 );
   result(idx) = 1

To go back:

 [~, back_result] = find(result);
 back_result = back_result - 1

[Michael Devereux]

Thanks!

Answer 2

[Greg Heath]

>> clear all

 classindices = [1 3 5 4 2 ];
 classmatrix  = full(ind2vec(classindices))

classmatrix =

     1     0     0     0     0
     0     0     0     0     1
     0     1     0     0     0
     0     0     0     1     0
     0     0     1     0     0

Hope this helps.

Greg