Add test_kernels.py file

Author: jaime-cespedes-sisniega

frouros/tests/unit/utils/test_kernels.py

@@ -0,0 +1,60 @@
+"""Test kernels module."""
+
+import numpy as np  # type: ignore
+import pytest  # type: ignore
+
+from frouros.utils.kernels import rbf_kernel
+
+
+# TODO: Create fixtures for the matrices and the expected kernel values
+
+@pytest.mark.parametrize(
+    "X, Y, sigma, expected_kernel_value",
+    [
+        (np.array([[1, 2, 3]]), np.array([[1, 2, 3]]), 0.5, np.array([[1.0]])),
+        (np.array([[1, 2, 3]]), np.array([[1, 2, 3]]), 1.0, np.array([[1.0]])),
+        (np.array([[1, 2, 3]]), np.array([[1, 2, 3]]), 2.0, np.array([[1.0]])),
+        (np.array([[1, 2, 3]]), np.array([[4, 5, 6]]), 0.5, np.array([[3.53262857e-24]])),
+        (np.array([[1, 2, 3]]), np.array([[4, 5, 6]]), 1.0, np.array([[1.37095909e-06]])),
+        (np.array([[1, 2, 3]]), np.array([[4, 5, 6]]), 2.0, np.array([[0.03421812]])),
+        (np.array([[1, 2, 3], [4, 5, 6]]), np.array([[1, 2, 3], [4, 5, 6]]), 0.5,
+         np.array([[1.00000000e+00, 3.53262857e-24], [3.53262857e-24, 1.00000000e+00]])),
+        (np.array([[1, 2, 3], [4, 5, 6]]), np.array([[1, 2, 3], [4, 5, 6]]), 1.0,
+         np.array([[1.00000000e+00, 1.37095909e-06], [1.37095909e-06, 1.00000000e+00]])),
+        (np.array([[1, 2, 3], [4, 5, 6]]), np.array([[1, 2, 3], [4, 5, 6]]), 2.0,
+         np.array([[1.00000000e+00, 0.03421812], [0.03421812, 1.00000000e+00]])),
+        (np.array([[1, 2, 3], [4, 5, 6]]), np.array([[1.5, 2.5, 3.5], [4.5,5.5, 6.5]]), 0.5,
+         np.array([[2.23130160e-01, 1.20048180e-32], [5.17555501e-17, 2.23130160e-01]])),
+        (np.array([[1, 2, 3], [4, 5, 6]]), np.array([[1.5, 2.5, 3.5], [4.5, 5.5, 6.5]]), 1.0,
+         np.array([[6.87289279e-01, 1.04674018e-08], [8.48182352e-05, 6.87289279e-01]])),
+        (np.array([[1, 2, 3], [4, 5, 6]]), np.array([[1.5, 2.5, 3.5], [4.5, 5.5, 6.5]]), 2.0,
+         np.array([[0.91051036, 0.01011486], [0.09596709, 0.91051036]])),
+    ],
+)
+def test_rbf_kernel(
+    X: np.ndarray,
+    Y: np.ndarray,
+    sigma: float,
+    expected_kernel_value: np.ndarray,
+) -> None:
+    """Test rbf kernel.
+
+    :param X: X values
+    :type X: numpy.ndarray
+    :param Y: Y values
+    :type Y: numpy.ndarray
+    :param sigma: sigma value
+    :type sigma: float
+    :param expected_kernel_value: expected kernel value
+    :type expected_kernel_value: numpy.ndarray
+    """
+    assert np.all(
+        np.isclose(
+            rbf_kernel(
+                X=X,
+                Y=Y,
+                sigma=sigma,
+            ),
+            expected_kernel_value,
+        ),
+    )