title: Matlab - Indexing an array by using string values
body: <p>I have a predefined array of 20 position which correspond to 20 joint out of my body. The joints are marked with string values (e.g. 'left_knee', 'head', 'left_eye', etc.). </p>
  
  <p>I want to refer to a certain value within the array by using the attached string value. For example I want to store the position of the observed joints. Initially all the position within the array are <code>(-1 , -1)</code> and then if I spot a certain joint I want to do something like <code>Joints('left_knee') = [100 200]</code>. </p>
  
  <p>How can I do this in Matlab?</p>