title: transform categorical predictors to numerical variable matlab
body: <p>I am new to matlab.
  I have a categorical input predictor(X) and the set of past results (Y, binary).
  I would like to convert it to numeric variable in the following method.
  For each category calculate the average of Y and replace the value with the average.
  for example:</p>
  
  <pre><code>  X    Y    X'
    1    1    1
    2    0    0
    3    1    0.5
    1    1    1
    2    0    0
    3    0    0.5
  </code></pre>
  
  <p>Please help.</p>