title: pyspark matrix with dummy variables
body: <p>Have two columns:</p>
  
  <pre><code>ID  Text
  1    a
  2    b
  3    c
  </code></pre>
  
  <p>How can I able to create matrix with dummy variables like this:</p>
  
  <pre><code>ID a b c
  1  1 0 0
  2  0 1 0
  3  0 0 1
  </code></pre>
  
  <p>Using pyspark library and its features?</p>