python-control · murrayrm · Feb 3, 2025 · Feb 1, 2025 · Feb 1, 2025 · Feb 1, 2025
diff --git a/.github/scripts/set-conda-test-matrix.py b/.github/scripts/set-conda-test-matrix.py
@@ -1,8 +1,5 @@
-""" set-conda-test-matrix.py
+"""Create test matrix for conda packages in OS/BLAS test matrix workflow."""
 
-Create test matrix for conda packages
-"""
-import json, re
 from pathlib import Path
 
 osmap = {'linux': 'ubuntu',

diff --git a/.github/scripts/set-pip-test-matrix.py b/.github/scripts/set-pip-test-matrix.py
@@ -1,7 +1,5 @@
-""" set-pip-test-matrix.py
+"""Create test matrix for pip wheels in OS/BLAS test matrix workflow."""
 
-Create test matrix for pip wheels
-"""
 import json
 from pathlib import Path
 

diff --git a/control/tests/bdalg_test.py b/control/tests/bdalg_test.py
@@ -1,24 +1,21 @@
-"""bdalg_test.py - test suite for block diagram algebra
+"""bdalg_test.py - test suite for block diagram algebra.
 
 RMM, 30 Mar 2011 (based on TestBDAlg from v0.4a)
 """
 
+import control as ctrl
 import numpy as np
-from numpy import sort
 import pytest
-
-import control as ctrl
-from control.xferfcn import TransferFunction, _tf_close_coeff
+from control.bdalg import _ensure_tf, append, connect, feedback
+from control.lti import poles, zeros
 from control.statesp import StateSpace
-from control.bdalg import feedback, append, connect
-from control.lti import zeros, poles
-from control.bdalg import _ensure_tf
+from control.tests.conftest import assert_tf_close_coeff
+from control.xferfcn import TransferFunction
+from numpy import sort
 
 
 class TestFeedback:
-    """These are tests for the feedback function in bdalg.py.  Currently, some
-    of the tests are not implemented, or are not working properly.  TODO: these
-    need to be fixed."""
+    """Tests for the feedback function in bdalg.py."""
 
     @pytest.fixture
     def tsys(self):
@@ -180,7 +177,7 @@ def testTFTF(self, tsys):
                                              [[[1., 4., 9., 8., 5.]]])
 
     def testLists(self, tsys):
-        """Make sure that lists of various lengths work for operations"""
+        """Make sure that lists of various lengths work for operations."""
         sys1 = ctrl.tf([1, 1], [1, 2])
         sys2 = ctrl.tf([1, 3], [1, 4])
         sys3 = ctrl.tf([1, 5], [1, 6])
@@ -237,7 +234,7 @@ def testLists(self, tsys):
             sort(zeros(sys1 + sys2 + sys3 + sys4 + sys5)))
 
     def testMimoSeries(self, tsys):
-        """regression: bdalg.series reverses order of arguments"""
+        """regression: bdalg.series reverses order of arguments."""
         g1 = ctrl.ss([], [], [], [[1, 2], [0, 3]])
         g2 = ctrl.ss([], [], [], [[1, 0], [2, 3]])
         ref = g2 * g1
@@ -430,9 +427,9 @@ class TestEnsureTf:
         ],
     )
     def test_ensure(self, arraylike_or_tf, dt, tf):
-        """Test nominal cases"""
+        """Test nominal cases."""
         ensured_tf = _ensure_tf(arraylike_or_tf, dt)
-        assert _tf_close_coeff(tf, ensured_tf)
+        assert_tf_close_coeff(tf, ensured_tf)
 
     @pytest.mark.parametrize(
         "arraylike_or_tf, dt, exception",
@@ -460,7 +457,7 @@ def test_ensure(self, arraylike_or_tf, dt, tf):
         ],
     )
     def test_error_ensure(self, arraylike_or_tf, dt, exception):
-        """Test error cases"""
+        """Test error cases."""
         with pytest.raises(exception):
             _ensure_tf(arraylike_or_tf, dt)
 
@@ -624,7 +621,7 @@ class TestTfCombineSplit:
     def test_combine_tf(self, tf_array, tf):
         """Test combining transfer functions."""
         tf_combined = ctrl.combine_tf(tf_array)
-        assert _tf_close_coeff(tf_combined, tf)
+        assert_tf_close_coeff(tf_combined, tf)
 
     @pytest.mark.parametrize(
         "tf_array, tf",
@@ -712,12 +709,12 @@ def test_split_tf(self, tf_array, tf):
         # Test entry-by-entry
         for i in range(tf_split.shape[0]):
             for j in range(tf_split.shape[1]):
-                assert _tf_close_coeff(
+                assert_tf_close_coeff(
                     tf_split[i, j],
                     tf_array[i, j],
                 )
         # Test combined
-        assert _tf_close_coeff(
+        assert_tf_close_coeff(
             ctrl.combine_tf(tf_split),
             ctrl.combine_tf(tf_array),
         )

diff --git a/control/tests/conftest.py b/control/tests/conftest.py
@@ -1,4 +1,4 @@
-"""conftest.py - pytest local plugins and fixtures"""
+"""conftest.py - pytest local plugins, fixtures, marks and functions."""
 
 import os
 from contextlib import contextmanager
@@ -9,6 +9,7 @@
 
 import control
 
+
 # some common pytest marks. These can be used as test decorators or in
 # pytest.param(marks=)
 slycotonly = pytest.mark.skipif(
@@ -61,7 +62,7 @@ def mplcleanup():
 
 @pytest.fixture(scope="function")
 def legacy_plot_signature():
-    """Turn off warnings for calls to plotting functions with old signatures"""
+    """Turn off warnings for calls to plotting functions with old signatures."""
     import warnings
     warnings.filterwarnings(
         'ignore', message='passing systems .* is deprecated',
@@ -75,14 +76,51 @@ def legacy_plot_signature():
 
 @pytest.fixture(scope="function")
 def ignore_future_warning():
-    """Turn off warnings for functions that generate FutureWarning"""
+    """Turn off warnings for functions that generate FutureWarning."""
     import warnings
     warnings.filterwarnings(
         'ignore', message='.*deprecated', category=FutureWarning)
     yield
     warnings.resetwarnings()
-
 
-# Allow pytest.mark.slow to mark slow tests (skip with pytest -m "not slow")
+
 def pytest_configure(config):
+    """Allow pytest.mark.slow to mark slow tests.
+
+    skip with pytest -m "not slow"
+    """
     config.addinivalue_line("markers", "slow: mark test as slow to run")
+
+
+def assert_tf_close_coeff(actual, desired, rtol=1e-5, atol=1e-8):
+    """Check if two transfer functions have close coefficients.
+
+    Parameters
+    ----------
+    actual, desired : TransferFunction
+        Transfer functions to compare.
+    rtol : float
+        Relative tolerance for ``np.testing.assert_allclose``.
+    atol : float
+        Absolute tolerance for ``np.testing.assert_allclose``.
+
+    Raises
+    ------
+    AssertionError
+    """
+    # Check number of outputs and inputs
+    assert actual.noutputs == desired.noutputs
+    assert actual.ninputs == desired.ninputs
+    # Check timestep
+    assert  actual.dt == desired.dt
+    # Check coefficient arrays
+    for i in range(actual.noutputs):
+        for j in range(actual.ninputs):
+            np.testing.assert_allclose(
+                actual.num[i][j],
+                desired.num[i][j],
+                rtol=rtol, atol=atol)
+            np.testing.assert_allclose(
+                actual.den[i][j],
+                desired.den[i][j],
+                rtol=rtol, atol=atol)