title: InvocationException: GraphViz's executables not found
body: <p>I'm unable to visualize or write the Decision tree. How can I go about it?</p>
  
  <p>Python version 3.5, Anaconda 3, I have even set the environment variables</p>
  
  <pre><code>    from sklearn import tree
      model = tree.DecisionTreeClassifier(criterion='gini') 
      model=tree.DecisionTreeClassifier()
      model.fit(trainData,trainLabel)
      model.score(trainData,trainLabel)
      predicted= model.predict(testData)
  
      from sklearn.externals.six import StringIO
      import pydot 
      import pydotplus
      dot_data = StringIO() 
      tree.export_graphviz(model, out_file=dot_data) 
      graph = pydotplus.graph_from_dot_data(dot_data.getvalue()) 
      print(graph)
      graph.write_pdf("C:\\Users\\anagha\\Desktop\\SynehackData\\DATA\\DATA\\graph.pdf") 
  </code></pre>
  
  <p>error :</p>
  
  <pre><code>InvocationException: GraphViz's executables not found
  </code></pre>