title: lingpipe sentiment analysis tutorial demo error?
body: <p>I was doing the sentiment analysis a from lingpipe website tutorial, and I keep getting this error, is there anyone wo can help?</p>
  
  <pre><code>java -cp "sentimentDemo.jar:../../../lingpipe
  
  e-4.1.0.jar" PolarityBasic file:///Users/dylan/Desktop/POLARITY_DIR/
  BASIC POLARITY DEMO
  
  Data Directory=file:/Users/dylan/Desktop/POLARITY_DIR/txt_sentoken
  Thrown: java.lang.NullPointerException
  java.lang.NullPointerException
  at com.aliasi.classify.DynamicLMClassifier.createNGramProcess(DynamicLMClassifier.java:313)
  at PolarityBasic.&lt;init&gt;(PolarityBasic.java:26)
  at PolarityBasic.main(PolarityBasic.java:92)
  </code></pre>