Update plotlog.py

Author: peterzhang2029

benchmark/paddle/image/plotlog.py

@@ -79,10 +79,10 @@ def plot_metric(metric,
     plt.figure()
     plt.title(graph_title)
     if line_num == 1:
-        plt.plot(batch_id, metric, line_style, line_label)
+        plt.plot(batch_id, metric, line_style, label=line_label)
     else:
         for i in range(line_num):
-            plt.plot(batch_id, metric[i], line_style[i], line_label[i])
+            plt.plot(batch_id, metric[i], line_style[i], label=line_label[i])
     plt.xlabel('batch')
     plt.ylabel(graph_title)
     plt.legend()
@@ -102,12 +102,12 @@ def main():
     accuracy_sample = sample(accuracy, args.sample_rate)
 
     plot_metric(loss_sample, batch_sample, 'loss', line_label='loss')
-    plot_metric(accuracy_sample,
-                batch_sample,
-                'accuracy',
-                line_style='g-',
-                line_label='accuracy')
-
+    plot_metric(
+        accuracy_sample,
+        batch_sample,
+        'accuracy',
+        line_style='g-',
+        line_label='accuracy')
 
 if __name__ == '__main__':
     main()