From d9affba4bf8736bdcd3c4b327913a3e2924918a2 Mon Sep 17 00:00:00 2001 From: Richard Murray Date: Sun, 23 Mar 2025 22:39:23 -0400 Subject: [PATCH 1/2] add error checks, unit tests, documentation for real-valued systems --- control/tests/statesp_test.py | 1 + control/tests/xferfcn_test.py | 4 ++++ control/xferfcn.py | 6 +++++- doc/linear.rst | 5 +++-- 4 files changed, 13 insertions(+), 3 deletions(-) diff --git a/control/tests/statesp_test.py b/control/tests/statesp_test.py index e3d78bbdd..3c1411f04 100644 --- a/control/tests/statesp_test.py +++ b/control/tests/statesp_test.py @@ -136,6 +136,7 @@ def test_constructor(self, sys322ABCD, dt, argfun): ((np.ones((3, 3)), np.ones((3, 2)), np.ones((2, 3)), np.ones((2, 3))), ValueError, r"Incompatible dimensions of D matrix; expected \(2, 2\)"), + (([1j], 2, 3, 0), TypeError, "real number, not 'complex'"), ]) def test_constructor_invalid(self, args, exc, errmsg): """Test invalid input to StateSpace() constructor""" diff --git a/control/tests/xferfcn_test.py b/control/tests/xferfcn_test.py index 87c852395..d3db08ef6 100644 --- a/control/tests/xferfcn_test.py +++ b/control/tests/xferfcn_test.py @@ -49,6 +49,10 @@ def test_constructor_bad_input_type(self): [[4, 5], [6, 7]]], [[[6, 7], [4, 5]], [[2, 3]]]) + + with pytest.raises(TypeError, match="unsupported data type"): + ct.tf([1j], [1, 2, 3]) + # good input TransferFunction([[[0, 1], [2, 3]], [[4, 5], [6, 7]]], diff --git a/control/xferfcn.py b/control/xferfcn.py index 16d7c5054..02ba72df4 100644 --- a/control/xferfcn.py +++ b/control/xferfcn.py @@ -1954,6 +1954,7 @@ def _clean_part(data, name=""): """ valid_types = (int, float, complex, np.number) + unsupported_types = (complex, np.complexfloating) valid_collection = (list, tuple, ndarray) if isinstance(data, np.ndarray) and data.ndim == 2 and \ @@ -1998,8 +1999,11 @@ def _clean_part(data, name=""): for i in range(out.shape[0]): for j in range(out.shape[1]): for k in range(len(out[i, j])): - if isinstance(out[i, j][k], (int, np.int32, np.int64)): + if isinstance(out[i, j][k], (int, np.integer)): out[i, j][k] = float(out[i, j][k]) + elif isinstance(out[i, j][k], unsupported_types): + raise TypeError( + f"unsupported data type: {type(out[i, j][k])}") return out diff --git a/doc/linear.rst b/doc/linear.rst index b7b8f7137..a9960feca 100644 --- a/doc/linear.rst +++ b/doc/linear.rst @@ -39,7 +39,7 @@ of linear time-invariant (LTI) systems: y &= C x + D u where :math:`u` is the input, :math:`y` is the output, and :math:`x` -is the state. +is the state. All vectors and matrices must be real-valued. To create a state space system, use the :func:`ss` function: @@ -94,7 +94,8 @@ transfer functions {b_0 s^n + b_1 s^{n-1} + \cdots + b_n}, where :math:`n` is greater than or equal to :math:`m` for a proper -transfer function. Improper transfer functions are also allowed. +transfer function. Improper transfer functions are also allowed. All +coefficients must be real-valued. To create a transfer function, use the :func:`tf` function:: From 6b4501e53bfd89f1970591af1fbc54d5f44ae50a Mon Sep 17 00:00:00 2001 From: Richard Murray Date: Sun, 23 Mar 2025 23:00:49 -0400 Subject: [PATCH 2/2] fix unintended use of complex coefficient in examples/cruise.ipynb --- examples/cruise.ipynb | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/examples/cruise.ipynb b/examples/cruise.ipynb index 16935b15e..08a1583ac 100644 --- a/examples/cruise.ipynb +++ b/examples/cruise.ipynb @@ -420,8 +420,8 @@ "name": "stdout", "output_type": "stream", "text": [ - "system: a = (0.010124405669387215-0j) , b = (1.3203061238159202+0j)\n", - "pzcancel: kp = 0.5 , ki = (0.005062202834693608+0j) , 1/(kp b) = (1.5148002148317266+0j)\n", + "system: a = 0.010124405669387215 , b = 1.3203061238159202\n", + "pzcancel: kp = 0.5 , ki = 0.005062202834693608 , 1/(kp b) = 1.5148002148317266\n", "sfb_int: K = 0.5 , ki = 0.1\n" ] }, @@ -442,7 +442,7 @@ "\n", "# Construction a controller that cancels the pole\n", "kp = 0.5\n", - "a = -P.poles()[0]\n", + "a = -P.poles()[0].real\n", "b = np.real(P(0)) * a\n", "ki = a * kp\n", "control_pz = ct.TransferFunction(\n",