Add rot_3D and tests for rot_2D/rot_3D

test/test_matrixmania/test_rot.py

@@ -0,0 +1,58 @@
+import math
+
+import pytest
+
+from matrixmania.compute import matmul, rot_2D, rot_3D, transpose
+
+
+def assert_matrix_close(actual, expected):
+    """Vergleicht zwei Matrizen elementweise mit Toleranz."""
+    assert len(actual) == len(expected)
+    for row_a, row_e in zip(actual, expected):
+        assert row_a == pytest.approx(row_e, abs=1e-9)
+
+
+# ---------- rot_2D ----------
+
+def test_rot_2D_zero():
+    assert_matrix_close(rot_2D(0), [[1, 0], [0, 1]])
+
+
+def test_rot_2D_90_degree():
+    assert_matrix_close(rot_2D(math.pi / 2), [[0, -1], [1, 0]])
+
+
+def test_rot_2D_invalid_input():
+    with pytest.raises(TypeError):
+        rot_2D("abc")
+
+
+# ---------- rot_3D ----------
+
+@pytest.mark.parametrize("axis", ["x", "y", "z"])
+def test_rot_3D_zero_is_identity(axis):
+    assert_matrix_close(rot_3D(0, axis), [[1, 0, 0], [0, 1, 0], [0, 0, 1]])
+
+
+@pytest.mark.parametrize(
+    "axis, expected",
+    [
+        ("x", [[1, 0, 0], [0, 0, -1], [0, 1, 0]]),
+        ("y", [[0, 0, 1], [0, 1, 0], [-1, 0, 0]]),
+        ("z", [[0, -1, 0], [1, 0, 0], [0, 0, 1]]),
+    ],
+)
+def test_rot_3D_90_degree(axis, expected):
+    assert_matrix_close(rot_3D(math.pi / 2, axis), expected)
+
+
+@pytest.mark.parametrize("axis", ["x", "y", "z"])
+def test_rot_3D_is_orthogonal(axis):
+    r = rot_3D(1.0, axis)
+    assert_matrix_close(matmul(r, transpose(r)), [[1, 0, 0], [0, 1, 0], [0, 0, 1]])
+
+
+@pytest.mark.parametrize("axis", ["w", "X", "", "xy"])
+def test_rot_3D_invalid_axis(axis):
+    with pytest.raises(ValueError):
+        rot_3D(1.0, axis)