title: finding locations of a set of elements in a matrix - Matlab
body: <p>I have a matrix A .
  I want to find all the unique elements is A so:
  b = unique(A);  will give array of all the unique elements in A.</p>
  
  <p>I want to find the locations of these elements in A. To be precise, the elements in b 
  repeat themselves in A and I want to find for each element in b its <strong>rows</strong> in A. </p>
  
  <p>How one can do that without a loop?</p>