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

indexingneural network

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

Best Answer

   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
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