Fix warning messages in python3 tests

cwrowley · cwrowley · commit b798bfa1cbd9 · 2014-08-13T22:05:28.000-04:00
Avoid using a deprecated call to pyplot.savefig, and eliminate
a superfluous print statement in xferfun._common_den
diff --git a/control/tests/frd_test.py b/control/tests/frd_test.py
@@ -174,10 +174,10 @@ def testNyquist(self):
         omega = np.logspace(-1, 2, 40)
         f1 = FRD(h1, omega, smooth=True)
         freqplot.nyquist(f1, np.logspace(-1, 2, 100))
-        plt.savefig('/dev/null', format='svg')
+        # plt.savefig('/dev/null', format='svg')
         plt.figure(2)
         freqplot.nyquist(f1, f1.omega)
-        plt.savefig('/dev/null', format='svg')
+        # plt.savefig('/dev/null', format='svg')
 
     def testMIMO(self):
         sys = StateSpace([[-0.5, 0.0], [0.0, -1.0]],
diff --git a/control/xferfcn.py b/control/xferfcn.py
@@ -871,10 +871,6 @@ def _common_den(self, imag_tol=None):
                        poles[n].imag * poles[n+m].imag > 0):
                     m += 1
 
-                if (m > 1):
-                    print("Found pole with multiplicity %d" % m)
-                    # print("Poles = ", poles)
-
                 # Multiple pairs from the outside in
                 for i in range(m):
                     quad = polymul([1., -poles[n]], [1., -poles[n+2*(m-i)-1]])
