fix bug in namedio unit test that was treating static SS systems the same as transfer functions. tests to track down missing names on some systems when converting to LinearIOSystem

sawyerbfuller · sawyerbfuller · commit 78f5aec6f35b · 2023-04-17T15:58:05.000-07:00
diff --git a/control/tests/namedio_test.py b/control/tests/namedio_test.py
@@ -90,8 +90,10 @@ def test_named_ss():
      (lambda t, x, u, params: -x, None),
      {'inputs': 2, 'outputs':2, 'states':2}],
     [ct.ss, ([[1, 2], [3, 4]], [[0], [1]], [[1, 0]], 0), {}],
+    [ct.ss, ([], [], [], 3), {}], # static system
     [ct.StateSpace, ([[1, 2], [3, 4]], [[0], [1]], [[1, 0]], 0), {}],
     [ct.tf, ([1, 2], [3, 4, 5]), {}],
+    [ct.tf, (2, 3), {}], # static system
     [ct.TransferFunction, ([1, 2], [3, 4, 5]), {}],
 ])
 def test_io_naming(fun, args, kwargs):
@@ -112,7 +114,7 @@ def test_io_naming(fun, args, kwargs):
     assert sys_g.name == 'sys[0]'
     assert sys_g.input_labels == [f'u[{i}]' for i in range(sys_g.ninputs)]
     assert sys_g.output_labels == [f'y[{i}]' for i in range(sys_g.noutputs)]
-    if sys_g.nstates:
+    if sys_g.nstates is not None:
         assert sys_g.state_labels == [f'x[{i}]' for i in range(sys_g.nstates)]
 
     #
@@ -128,7 +130,7 @@ def test_io_naming(fun, args, kwargs):
     sys_r.set_outputs(output_labels)
     assert sys_r.output_labels == output_labels
 
-    if sys_g.nstates:
+    if sys_g.nstates is not None:
         state_labels = [f'x{i}' for i in range(sys_g.nstates)]
         sys_r.set_states(state_labels)
         assert sys_r.state_labels == state_labels
@@ -143,7 +145,7 @@ def test_io_naming(fun, args, kwargs):
         sys_k = fun(state_labels, output_labels, input_labels, name='mysys')
 
     elif sys_g.nstates is None:
-        # Don't pass state labels
+        # Don't pass state labels if TransferFunction
         sys_k = fun(
             *args, inputs=input_labels, outputs=output_labels, name='mysys')
 
@@ -155,7 +157,7 @@ def test_io_naming(fun, args, kwargs):
     assert sys_k.name == 'mysys'
     assert sys_k.input_labels == input_labels
     assert sys_k.output_labels == output_labels
-    if sys_g.nstates:
+    if sys_g.nstates is not None:
         assert sys_k.state_labels == state_labels
 
     #
@@ -193,6 +195,24 @@ def test_io_naming(fun, args, kwargs):
         assert sys_tf.input_labels == input_labels
         assert sys_tf.output_labels == output_labels
 
+    #
+    # Convert the system to a LinearIOSystem and make sure labels transfer
+    #
+    if not isinstance(
+            sys_r, (ct.FrequencyResponseData, ct.NonlinearIOSystem)) and \
+                    ct.slycot_check():
+        sys_lio = ct.LinearIOSystem(sys_r)
+        assert sys_lio != sys_r
+        assert sys_lio.input_labels == input_labels
+        assert sys_lio.output_labels == output_labels
+
+        # Reassign system and signal names
+        sys_lio = ct.LinearIOSystem(
+            sys_g, inputs=input_labels, outputs=output_labels, name='new')
+        assert sys_lio.name == 'new'
+        assert sys_lio.input_labels == input_labels
+        assert sys_lio.output_labels == output_labels
+
 
 # Internal testing of StateSpace initialization
 def test_init_namedif():
