Add plot and add more iterations to draw plot in jupyter (#546)

05.recommender_system/README.md

@@ -405,6 +405,11 @@ For example, we can check the cost by `trainer.test` when `EndStepEvent` occurs
 # Specify the directory path to save the parameters
 params_dirname = "recommender_system.inference.model"
 
+from paddle.v2.plot import Ploter
+test_title = "Test cost"
+plot_cost = Ploter(test_title)
+
+
 def event_handler(event):
     if isinstance(event, fluid.EndStepEvent):
         avg_cost_set = trainer.test(
@@ -412,12 +417,15 @@ def event_handler(event):
 
         # get avg cost
         avg_cost = np.array(avg_cost_set).mean()
+        
+        plot_cost.append(test_title, event.step, avg_cost_set[0])
+        plot_cost.plot()
 
         print("avg_cost: %s" % avg_cost)
         print('BatchID {0}, Test Loss {1:0.2}'.format(event.epoch + 1,
                                                           float(avg_cost)))
 
-        if float(avg_cost) < 4:
+        if event.step == 20: # Adjust this number for accuracy
             trainer.save_params(params_dirname)
             trainer.stop()