added test for aliases, added docstrings for alias stubs, removed alias for feedback and added stub to LTI

lkies · lkies · commit 566627b38c81 · 2025-01-10T14:49:22.000+01:00
diff --git a/control/__init__.py b/control/__init__.py
@@ -123,7 +123,6 @@
 # all heavily depend on the LTI class
 LTI.to_ss = ss
 LTI.to_tf = tf
-LTI.feedback = feedback
 LTI.bode_plot = bode_plot
 LTI.nyquist_plot = nyquist_plot
 LTI.nichols_plot = nichols_plot
diff --git a/control/lti.py b/control/lti.py
@@ -210,25 +210,33 @@ def ispassive(self):
         # importing here prevents circular dependancy
         from control.passivity import ispassive
         return ispassive(self)
+    
+    def feedback(self, other=1, sign=-1):
+        raise NotImplementedError(f"feedback not implemented for base {self.__class__.__name__} objects")
 
     # convenience aliases
     # most function are only forward declaraed and patched in the __init__.py to avoid circular imports
 
     # conversions
+    #: Convert to :class:`StateSpace` representation; see :func:`ss`
     to_ss: Callable
+    #: Convert to :class:`TransferFunction` representation; see :func:`tf`
     to_tf: Callable
 
-    # system interconnections
-    feedback: Callable
-
     # freq domain plotting
+    #: Bode plot; see :func:`bode_plot`
     bode_plot: Callable
+    #: Nyquist plot; see :func:`nyquist_plot`
     nyquist_plot: Callable
+    #: Nichols plot; see :func:`nichols_plot`
     nichols_plot: Callable
 
     # time domain simulation
+    #: Forced response; see :func:`forced_response`
     forced_response = control.timeresp.forced_response
+    #: Impulse response; see :func:`impulse_response`
     impulse_response = control.timeresp.impulse_response
+    #: Step response; see :func:`step_response`
     step_response = control.timeresp.step_response
 
 
diff --git a/control/tests/kwargs_test.py b/control/tests/kwargs_test.py
@@ -244,7 +244,7 @@ def test_response_plot_kwargs(data_fcn, plot_fcn, mimo):
     'append': test_unrecognized_kwargs,
     'bode': test_response_plot_kwargs,
     'bode_plot': test_response_plot_kwargs,
-    'LTI.bode_plot': test_response_plot_kwargs,
+    'LTI.bode_plot': test_response_plot_kwargs, # alias for bode_plot and tested via bode_plot
     'create_estimator_iosystem': stochsys_test.test_estimator_errors,
     'create_statefbk_iosystem': statefbk_test.TestStatefbk.test_statefbk_errors,
     'describing_function_plot': test_matplotlib_kwargs,
@@ -254,7 +254,6 @@ def test_response_plot_kwargs(data_fcn, plot_fcn, mimo):
     'dlqr': test_unrecognized_kwargs,
     'drss': test_unrecognized_kwargs,
     'feedback': test_unrecognized_kwargs,
-    'LTI.feedback': test_unrecognized_kwargs,
     'find_eqpt': iosys_test.test_find_operating_point,
     'find_operating_point': iosys_test.test_find_operating_point,
     'flatsys.flatsys': test_unrecognized_kwargs,
@@ -269,13 +268,13 @@ def test_response_plot_kwargs(data_fcn, plot_fcn, mimo):
     'lqr': test_unrecognized_kwargs,
     'negate': test_unrecognized_kwargs,
     'nichols_plot': test_matplotlib_kwargs,
-    'LTI.nichols_plot': test_matplotlib_kwargs,
+    'LTI.nichols_plot': test_matplotlib_kwargs, # alias for nichols_plot and tested via nichols_plot
     'nichols': test_matplotlib_kwargs,
     'nlsys': test_unrecognized_kwargs,
     'nyquist': test_matplotlib_kwargs,
     'nyquist_response': test_response_plot_kwargs,
     'nyquist_plot': test_matplotlib_kwargs,
-    'LTI.nyquist_plot': test_matplotlib_kwargs,
+    'LTI.nyquist_plot': test_matplotlib_kwargs, # alias for nyquist_plot and tested via nyquist_plot
     'phase_plane_plot': test_matplotlib_kwargs,
     'parallel': test_unrecognized_kwargs,
     'pole_zero_plot': test_unrecognized_kwargs,
diff --git a/control/tests/statesp_test.py b/control/tests/statesp_test.py
@@ -1281,3 +1281,31 @@ def test_tf2ss_mimo():
     else:
         with pytest.raises(ct.ControlMIMONotImplemented):
             sys_ss = ct.ss(sys_tf)
+
+def test_convenience_aliases():
+    sys = ct.StateSpace(1, 1, 1, 1)
+
+    # test that all the aliases point to the correct function
+    # .__funct__ a bound methods underlying function
+    assert sys.to_ss.__func__ == ct.ss
+    assert sys.to_tf.__func__ == ct.tf
+    assert sys.bode_plot.__func__ == ct.bode_plot
+    assert sys.nyquist_plot.__func__ == ct.nyquist_plot
+    assert sys.nichols_plot.__func__ == ct.nichols_plot
+    assert sys.forced_response.__func__ == ct.forced_response
+    assert sys.impulse_response.__func__ == ct.impulse_response
+    assert sys.step_response.__func__ == ct.step_response
+    assert sys.initial_response.__func__ == ct.initial_response
+
+    # make sure the functions can be used as member function ie they support
+    # an instance of StateSpace as the first argument and that they at least return
+    # the correct type
+    assert isinstance(sys.to_ss(), StateSpace)
+    assert isinstance(sys.to_tf(), TransferFunction)
+    assert isinstance(sys.bode_plot(), ct.ControlPlot)
+    assert isinstance(sys.nyquist_plot(), ct.ControlPlot)
+    assert isinstance(sys.nichols_plot(), ct.ControlPlot)
+    assert isinstance(sys.forced_response([0, 1], [1, 1]), (ct.TimeResponseData, ct.TimeResponseList))
+    assert isinstance(sys.impulse_response(), (ct.TimeResponseData, ct.TimeResponseList))
+    assert isinstance(sys.step_response(), (ct.TimeResponseData, ct.TimeResponseList))
+    assert isinstance(sys.initial_response(X0=1), (ct.TimeResponseData, ct.TimeResponseList))
