Add __mul__ and __rmul__ for frdata

sdahdah · sdahdah · commit a5fe1c17bdba · 2024-12-19T10:30:25.000-05:00
diff --git a/control/frdata.py b/control/frdata.py
@@ -20,6 +20,7 @@
 from scipy.interpolate import splev, splprep
 
 from . import config
+from . import bdalg
 from .exception import pandas_check
 from .iosys import InputOutputSystem, NamedSignal, _process_iosys_keywords, \
     _process_subsys_index, common_timebase
@@ -442,6 +443,12 @@ def __mul__(self, other):
         else:
             other = _convert_to_frd(other, omega=self.omega)
 
+        # Promote SISO object to compatible dimension
+        if self.issiso() and not other.issiso():
+            self = bdalg.append(*([self] * other.noutputs))
+        elif not self.issiso() and other.issiso():
+            other = bdalg.append(*([other] * self.ninputs))
+
         # Check that the input-output sizes are consistent.
         if self.ninputs != other.noutputs:
             raise ValueError(
@@ -469,6 +476,12 @@ def __rmul__(self, other):
         else:
             other = _convert_to_frd(other, omega=self.omega)
 
+        # Promote SISO object to compatible dimension
+        if self.issiso() and not other.issiso():
+            self = bdalg.append(*([self] * other.ninputs))
+        elif not self.issiso() and other.issiso():
+            other = bdalg.append(*([other] * self.noutputs))
+
         # Check that the input-output sizes are consistent.
         if self.noutputs != other.ninputs:
             raise ValueError(
diff --git a/control/tests/frd_test.py b/control/tests/frd_test.py
@@ -474,10 +474,19 @@ def test_operator_conversion(self):
         np.testing.assert_array_almost_equal(sys_add.omega, chk_add.omega)
         np.testing.assert_array_almost_equal(sys_add.fresp, chk_add.fresp)
 
+        # Test broadcasting with SISO system
+        sys_tf_mimo = TransferFunction([1], [1, 0]) * np.eye(2)
+        frd_tf_mimo = frd(sys_tf_mimo, np.logspace(-1, 1, 10))
+        result = FrequencyResponseData.__rmul__(frd_tf, frd_tf_mimo)
+        expected = frd(sys_tf_mimo * sys_tf, np.logspace(-1, 1, 10))
+        np.testing.assert_array_almost_equal(expected.omega, result.omega)
+        np.testing.assert_array_almost_equal(expected.fresp, result.fresp)
+
         # Input/output mismatch size mismatch in rmul
         sys1 = frd(ct.rss(2, 2, 2), np.logspace(-1, 1, 10))
+        sys2 = frd(ct.rss(3, 3, 3), np.logspace(-1, 1, 10))
         with pytest.raises(ValueError):
-            FrequencyResponseData.__rmul__(frd_2, sys1)
+            FrequencyResponseData.__rmul__(sys2, sys1)
 
         # Make sure conversion of something random generates exception
         with pytest.raises(TypeError):
