update _convert_to_transfer_function to allow 0D and 1D arrays

murrayrm · murrayrm · commit 8d30e76402fe · 2021-01-05T07:37:42.000-08:00
diff --git a/control/tests/bdalg_test.py b/control/tests/bdalg_test.py
@@ -255,7 +255,7 @@ def test_feedback_args(self, tsys):
             ctrl.feedback(*args)
 
         # If second argument is not LTI or convertable, generate an exception
-        args = (tsys.sys1, np.array([1]))
+        args = (tsys.sys1, 'hello world')
         with pytest.raises(TypeError):
             ctrl.feedback(*args)
 
diff --git a/control/tests/xferfcn_test.py b/control/tests/xferfcn_test.py
@@ -1023,8 +1023,8 @@ def test_returnScipySignalLTI_error(self, mimotf):
     [pytest.param(getattr(operator, s), id=s) for s in ('add', 'sub', 'mul')])
 @pytest.mark.parametrize(
     "tf, arr",
-    [# pytest.param(ct.tf([1], [0.5, 1]), np.array(2.), id="0D scalar"),
-     # pytest.param(ct.tf([1], [0.5, 1]), np.array([2.]), id="1D scalar"),
+    [pytest.param(ct.tf([1], [0.5, 1]), np.array(2.), id="0D scalar"),
+     pytest.param(ct.tf([1], [0.5, 1]), np.array([2.]), id="1D scalar"),
      pytest.param(ct.tf([1], [0.5, 1]), np.array([[2.]]), id="2D scalar")])
 def test_xferfcn_ndarray_precedence(op, tf, arr):
     # Apply the operator to the transfer function and array
diff --git a/control/xferfcn.py b/control/xferfcn.py
@@ -1314,7 +1314,7 @@ def _convert_to_transfer_function(sys, **kw):
 
     # If this is array-like, try to create a constant feedthrough
     try:
-        D = array(sys)
+        D = array(sys, ndmin=2)
         outputs, inputs = D.shape
         num = [[[D[i, j]] for j in range(inputs)] for i in range(outputs)]
         den = [[[1] for j in range(inputs)] for i in range(outputs)]
