Fix plot_fir

mbtrack2/tracking/feedback.py

@@ -208,13 +208,13 @@ class FIRDamper(Element) :
         
         fig, [ax1, ax2] = plt.subplots(1,2)
         ax1.plot(tune, gain)
-        ax1.title("Gain")
-        ax1.xlabel("Tune")
+        ax1.set_title("Gain")
+        ax1.set_xlabel("Tune")
         
         ax2.plot(tune, phase)
-        ax2.title("Phase in degree")
-        ax2.xlabel("Tune")
-        ax2.ylabel("Degree")
+        ax2.set_title("Phase in degree")
+        ax2.set_xlabel("Tune")
+        ax2.set_ylabel("Degree")
          
     def track(self, beam_or_bunch):
         """