TST: introduce testing for ND linear and rbf interpolations.

tests/unit/test_function.py

@@ -502,6 +502,110 @@ def test_3d_shepard_interpolation(x, y, z, w_expected):
     assert np.isclose(w_expected, w, atol=1e-8).all()
 
 
+@pytest.mark.parametrize(
+    "x,y,z_expected",
+    [
+        (1, 0, 0),
+        (0, 1, 0),
+        (0, 0, 1),
+        (0.5, 0.5, 0),
+        (0.25, 0.25, 0.5),
+        ([0, 0.5], [0, 0.5], [1, 0]),
+    ],
+)
+def test_2d_rbf_interpolation(x, y, z_expected):
+    """Test the rbf interpolation method of the Function class."""
+    # Test plane x + y + z = 1
+    source = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]
+    func = Function(
+        source=source, inputs=["x", "y"], outputs=["z"], interpolation="rbf"
+    )
+    z = func(x, y)
+    z_opt = func.get_value_opt(x, y)
+    assert np.isclose(z, z_opt, atol=1e-8).all()
+    assert np.isclose(z_expected, z, atol=1e-8).all()
+
+
+@pytest.mark.parametrize(
+    "x,y,z,w_expected",
+    [
+        (0, 0, 0, 1),
+        (1, 0, 0, 0),
+        (0, 1, 0, 0),
+        (0, 0, 1, 0),
+        (0.5, 0.5, 0.5, -0.5),
+        (0.25, 0.25, 0.25, 0.25),
+        ([0, 0.5], [0, 0.5], [0, 0.5], [1, -0.5]),
+    ],
+)
+def test_3d_rbf_interpolation(x, y, z, w_expected):
+    """Test the rbf interpolation method of the Function class."""
+    # Test plane x + y + z + w = 1
+    source = [(1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1)]
+    func = Function(
+        source=source, inputs=["x", "y", "z"], outputs=["w"], interpolation="rbf"
+    )
+    w = func(x, y, z)
+    w_opt = func.get_value_opt(x, y, z)
+    assert np.isclose(w, w_opt, atol=1e-8).all()
+    assert np.isclose(w_expected, w, atol=1e-8).all()
+
+
+@pytest.mark.parametrize(
+    "x,y,z_expected",
+    [
+        (1, 0, 0),
+        (0, 1, 0),
+        (0, 0, 1),
+        (0.5, 0.5, 0),
+        (0.25, 0.25, 0.5),
+        ([0, 0.5], [0, 0.5], [1, 0]),
+    ],
+)
+def test_2d_linear_interpolation(x, y, z_expected):
+    """Test the linear interpolation method of the Function class."""
+    # Test plane x + y + z = 1
+    source = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]
+    func = Function(
+        source=source, inputs=["x", "y"], outputs=["z"], interpolation="linear"
+    )
+    z = func(x, y)
+    z_opt = func.get_value_opt(x, y)
+    assert np.isclose(z, z_opt, atol=1e-8).all()
+    assert np.isclose(z_expected, z, atol=1e-8).all()
+
+
+@pytest.mark.parametrize(
+    "x,y,z,w_expected",
+    [
+        (1, 0, 0, 0),
+        (0, 1, 0, 0),
+        (0, 0, 1, 0),
+        (0, 0, 0, 1),
+        (0.5, 0.5, 0.5, -0.5),
+        (0.25, 0.25, 0.25, 0.25),
+        ([0, 0.25], [0, 0.25], [0, 0.25], [1, 0.25]),
+    ],
+)
+def test_3d_linear_interpolation(x, y, z, w_expected):
+    """Test the linear interpolation method of the Function class."""
+    # Test plane x + y + z + w = 1
+    source = [
+        (1, 0, 0, 0),
+        (0, 1, 0, 0),
+        (0, 0, 1, 0),
+        (0, 0, 0, 1),
+        (0.5, 0.5, 0.5, -0.5),
+    ]
+    func = Function(
+        source=source, inputs=["x", "y", "z"], outputs=["w"], interpolation="linear"
+    )
+    w = func(x, y, z)
+    w_opt = func.get_value_opt(x, y, z)
+    assert np.isclose(w, w_opt, atol=1e-8).all()
+    assert np.isclose(w_expected, w, atol=1e-8).all()
+
+
 @pytest.mark.parametrize("a", [-1, -0.5, 0, 0.5, 1])
 @pytest.mark.parametrize("b", [-1, -0.5, 0, 0.5, 1])
 def test_multivariate_function(a, b):
@@ -565,26 +669,6 @@ def test_set_discrete_based_on_2d_model(func_2d_from_csv):
     assert discretized_func.__extrapolation__ == func_2d_from_csv.__extrapolation__
 
 
-@pytest.mark.parametrize(
-    "x,y,z_expected",
-    [
-        (1, 0, 0),
-        (0, 1, 0),
-        (0, 0, 1),
-        (0.5, 0.5, 1 / 3),
-        (0.25, 0.25, 25 / (25 + 2 * 5**0.5)),
-        ([0, 0.5], [0, 0.5], [1, 1 / 3]),
-    ],
-)
-def test_shepard_interpolation(x, y, z_expected):
-    """Test the shepard interpolation method of the Function class."""
-    # Test plane x + y + z = 1
-    source = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]
-    func = Function(source=source, inputs=["x", "y"], outputs=["z"])
-    z = func(x, y)
-    assert np.isclose(z, z_expected, atol=1e-8).all()
-
-
 @pytest.mark.parametrize("other", [1, 0.1, np.int_(1), np.float64(0.1), np.array([1])])
 def test_sum_arithmetic_priority(other):
     """Test the arithmetic priority of the add operation of the Function class,