visualize regression tree

4_regression.py

@@ -31,7 +31,7 @@ print("data shape: ", df.shape)
 # reg_tree = tree.DecisionTreeRegressor()
 # knn = KNeighborsRegressor(n_neighbors=2)
 #
-# learner = knn
+# learner = reg_tree
 #
 # """" Train and apply """
 # learner.fit(X_train, y_train)
@@ -46,3 +46,10 @@ print("data shape: ", df.shape)
 # print("MSE  \t{0:5.2f}".format( metrics.mean_squared_error(y_test,y_pred)))
 # print("R2   \t{0:5.2f}".format( metrics.r2_score(y_test,y_pred)))
 #
+# # """ Visualize the tree """
+# # treeFileName = 'reg_tree.dot'
+# # tree.export_graphviz(learner, out_file='treeFileName.dot')
+#
+# # install GraphViz
+# # $ dot -Tps reg_tree.dot -o tree.ps      (PostScript format)
+# # $ dot -Tpng reg_tree.dot -o tree.png    (PNG format)