TST: add unit test for comparing return values of continuous/discrete sims

murrayrm · murrayrm · commit 1f9e46c94b05 · 2017-04-15T08:55:38.000-07:00
diff --git a/control/tests/timeresp_test.py b/control/tests/timeresp_test.py
@@ -14,7 +14,7 @@
 from control.timeresp import *
 from control.statesp import *
 from control.xferfcn import TransferFunction, _convertToTransferFunction
-
+from control.dtime import c2d
 
 class TestTimeresp(unittest.TestCase):
     def setUp(self):
@@ -77,6 +77,15 @@ def test_step_response(self):
         np.testing.assert_array_almost_equal(y_00, youttrue, decimal=4)
         np.testing.assert_array_almost_equal(y_11, youttrue, decimal=4)
 
+        # Make sure continuous and discrete time use same return conventions
+        sysc = self.mimo_ss1
+        sysd = c2d(sysc, 1)           # discrete time system
+        Tvec = np.linspace(0, 10, 11) # make sure to use integer times 0..10
+        Tc, youtc = step_response(sysc, Tvec, input=0)
+        Td, youtd = step_response(sysd, Tvec, input=0)
+        np.testing.assert_array_equal(Tc.shape, Td.shape)
+        np.testing.assert_array_equal(youtc.shape, youtd.shape)
+
     def test_impulse_response(self):
         # Test SISO system
         sys = self.siso_ss1
