FIX: development of parametrized tests for the singular_values_plot function

forgi86 · forgi86 · commit 762fbd6172c1 · 2021-03-31T15:04:51.000+02:00
diff --git a/control/tests/freqresp_test.py b/control/tests/freqresp_test.py
@@ -511,15 +511,82 @@ def test_dcgain_consistency():
     np.testing.assert_almost_equal(sys_ss.dcgain(), -1)
 
 
-def test_singular_values_plot():
-    den = [75, 1]
-    sys = tf([[[87.8], [-86.4]],
-              [[108.2], [-109.6]]],
-             [[den, den],
-              [den, den]])
-    sigma, omega = singular_values_plot(sys, 0.0)
-    sys_dc = np.array([[87.8, -86.4],
-                       [108.2, -109.6]])
-
-    u, s, v = np.linalg.svd(sys_dc)
-    np.testing.assert_almost_equal(sigma.ravel(), s.ravel())
+# Testing of the singular_value_plot_function
+class TSys:
+    """Struct of test system"""
+    def __init__(self, sys=None, call_kwargs=None):
+        self.sys = sys
+        self.kwargs = call_kwargs if call_kwargs else {}
+
+    def __repr__(self):
+        """Show system when debugging"""
+        return self.sys.__repr__()
+
+
+@pytest.fixture
+def ss_mimo_t():
+    A = np.diag([-1/75.0, -1/75.0])
+    B = np.array([[87.8, -86.4],
+                  [108.2, -109.6]])/75.0
+    C = np.eye(2)
+    D = np.zeros((2, 2))
+    T = TSys(ss(A, B, C, D))
+    T.omega = 0.0
+    T.sigma = np.array([[197.20868123, 1.39141948]])
+    return T
+
+
+@pytest.fixture
+def ss_miso_t():
+    A = np.diag([-1 / 75.0])
+    B = np.array([[87.8, -86.4]]) / 75.0
+    C = np.array([[1]])
+    D = np.zeros((1, 2))
+    T = TSys(ss(A, B, C, D))
+    T.omega = 0.0
+    T.sigma = np.array([[123.1819792]])
+    return T
+
+
+@pytest.fixture
+def ss_simo_t():
+    A = np.diag([-1 / 75.0])
+    B = np.array([[1.0]]) / 75.0
+    C = np.array([[87.8], [108.2]])
+    D = np.zeros((2, 1))
+    T = TSys(ss(A, B, C, D))
+    T.omega = 0.0
+    T.sigma = np.array([[139.34159465]])
+    return T
+
+
+@pytest.fixture
+def ss_siso_t():
+    A = np.diag([-1 / 75.0])
+    B = np.array([[1.0]]) / 75.0
+    C = np.array([[87.8]])
+    D = np.zeros((1, 1))
+    T = TSys(ss(A, B, C, D))
+    T.omega = 0.0
+    T.sigma = np.array([[87.8]])
+    return T
+
+
+@pytest.fixture
+def tsystem(request, ss_mimo_t, ss_miso_t, ss_simo_t):
+
+    systems = {"ss_mimo": ss_mimo_t,
+               "ss_miso": ss_miso_t,
+               "ss_simo": ss_simo_t,
+               "ss_siso": ss_simo_t
+               }
+    return systems[request.param]
+
+
+@pytest.mark.parametrize("tsystem", ["ss_mimo", "ss_miso", "ss_simo", "ss_siso"], indirect=["tsystem"])
+def test_singular_values_plot(tsystem):
+    sys = tsystem.sys
+    omega = tsystem.omega
+    sigma_check = tsystem.sigma
+    sigma, omega = singular_values_plot(sys, omega, plot=False)
+    np.testing.assert_almost_equal(sigma, sigma_check)
