Make quad integration measures stateless (#748)

src/probnum/quad/_utils.py

@@ -53,12 +53,11 @@ def as_domain(
     """
     if input_dim is not None and input_dim < 1:
         raise ValueError(
-            f"If given, input dimension must be positive. Current value "
-            f"is ({input_dim})."
+            f"Input dimension must be positive. Current value is ({input_dim})."
         )
 
     if len(domain) != 2:
-        raise ValueError(f"domain must be of length 2 ({len(domain)}).")
+        raise ValueError(f"'domain' must be of length 2 ({len(domain)}).")
 
     # Domain limits must have equal dimensions
     if np.size(domain[0]) != np.size(domain[1]):
@@ -85,8 +84,8 @@ def as_domain(
         # Size of domain and input dimension do not match
         if input_dim != domain_dim:
             raise ValueError(
-                "If domain limits are not scalars, their lengths "
-                "must match the input dimension."
+                f"If domain limits are not scalars, their lengths "
+                f"must match the input dimension ({input_dim})."
             )
         domain_a = domain[0]
         domain_b = domain[1]

src/probnum/quad/integration_measures/_integration_measure.py

@@ -54,7 +54,7 @@ def __call__(self, points: Union[FloatLike, np.ndarray]) -> np.ndarray:
     def sample(
         self,
         n_sample: IntLike,
-        rng: Optional[np.random.Generator] = np.random.default_rng(),
+        rng: np.random.Generator,
     ) -> np.ndarray:
         """Sample ``n_sample`` points from the integration measure.
 
@@ -63,7 +63,7 @@ def sample(
         n_sample
             Number of points to be sampled
         rng
-            Random number generator. Optional. Default is `np.random.default_rng()`.
+            A Random number generator.
 
         Returns
         -------

src/probnum/quad/integration_measures/_lebesgue_measure.py

@@ -65,7 +65,7 @@ def __call__(self, points: np.ndarray) -> np.ndarray:
     def sample(
         self,
         n_sample: IntLike,
-        rng: Optional[np.random.Generator] = np.random.default_rng(),
+        rng: np.random.Generator,
     ) -> np.ndarray:
         return self.random_variable.rvs(
             size=(n_sample, self.input_dim), random_state=rng

tests/test_quad/test_bq_utils.py

@@ -10,12 +10,15 @@
 @pytest.mark.parametrize(
     "dom, in_dim",
     [
+        ((0, 1), 0),  # zero dimension
         ((0, 1), -2),  # negative dimension
         ((np.zeros(2), np.ones(2)), 3),  # length of bounds does not match dimension
         ((np.zeros(2), np.ones(3)), None),  # lower and upper bounds not equal lengths
         ((np.array([0, 0]), np.array([1, 0])), None),  # integration domain is empty
         ((np.zeros([2, 1]), np.ones([2, 1])), None),  # bounds have too many dimensions
         ((np.zeros([2, 1]), np.ones([2, 1])), 2),  # bounds have too many dimensions
+        ((0, 1, 2), 2),  # domain has too many elements
+        ((-np.ones(2), np.zeros(2), np.ones(2)), 2),  # domain has too many elements
     ]
 )
 def test_as_domain_wrong_input(dom, in_dim):

tests/test_quad/test_integration_measure.py

@@ -5,9 +5,25 @@
 
 from probnum.quad.integration_measures import GaussianMeasure, LebesgueMeasure
 
+# Tests shared by all measures start here
 
-# Tests for Gaussian measure
-def test_gaussian_diagonal_covariance(input_dim: int):
+
+def test_density_call_shape(x, measure):
+    expected_shape = (x.shape[0],)
+    assert measure(x).shape == expected_shape
+
+
+@pytest.mark.parametrize("n_sample", [1, 2, 5])
+def test_sample_shape(measure, n_sample, rng):
+    input_dim = measure.input_dim
+    res = measure.sample(n_sample=n_sample, rng=rng)
+    assert res.shape == (n_sample, input_dim)
+
+
+# Tests for Gaussian measure start here
+
+
+def test_gaussian_diagonal_covariance(input_dim):
     """Check that diagonal covariance matrices are recognised as diagonal."""
     mean = np.full((input_dim,), 0.0)
     cov = np.eye(input_dim)
@@ -36,13 +52,6 @@ def test_gaussian_mean_shape_1d(mean, cov):
     assert measure.cov.size == 1
 
 
-@pytest.mark.parametrize("neg_dim", [0, -1, -10, -100])
-def test_gaussian_negative_dimension(neg_dim):
-    """Make sure that a negative dimension raises ValueError."""
-    with pytest.raises(ValueError):
-        GaussianMeasure(0, 1, neg_dim)
-
-
 def test_gaussian_param_assignment(input_dim: int):
     """Check that diagonal mean and covariance for higher dimensions are extended
     correctly."""
@@ -57,15 +66,24 @@ def test_gaussian_param_assignment(input_dim: int):
         assert np.array_equal(measure.cov, np.eye(input_dim))
 
 
-def test_gaussian_scalar():
+def test_gaussian_param_assignment_scalar():
     """Check that the 1d Gaussian case works."""
     measure = GaussianMeasure(0.5, 1.5)
     assert measure.mean == 0.5
     assert measure.cov == 1.5
 
 
-# Tests for Lebesgue measure
-def test_lebesgue_dim_correct(input_dim: int):
+@pytest.mark.parametrize("wrong_dim", [0, -1, -10, -100])
+def test_gaussian_wrong_dimension_raises(wrong_dim):
+    """Make sure that a non-positive dimension raises ValueError."""
+    with pytest.raises(ValueError):
+        GaussianMeasure(0, 1, wrong_dim)
+
+
+# Tests for Lebesgue measure start here
+
+
+def test_lebesgue_input_dim_assignment(input_dim: int):
     """Check that dimensions are handled correctly."""
     domain1 = (0.0, 1.87)
     measure11 = LebesgueMeasure(domain=domain1)
@@ -82,40 +100,70 @@ def test_lebesgue_dim_correct(input_dim: int):
     assert measure22.input_dim == input_dim
 
 
-@pytest.mark.parametrize("domain_a", [0, np.full((3,), 0), np.full((13,), 0)])
-@pytest.mark.parametrize("domain_b", [np.full((4,), 1.2), np.full((14,), 1.2)])
-@pytest.mark.parametrize("input_dim", [-10, -2, 0, 2, 12, 122])
-def test_lebesgue_dim_incorrect(domain_a, domain_b, input_dim):
-    """Check that ValueError is raised if domain limits have mismatching dimensions or
-    dimension is not positive."""
-    with pytest.raises(ValueError):
-        LebesgueMeasure(domain=(domain_a, domain_b), input_dim=input_dim)
-
-
-def test_lebesgue_normalization(input_dim: int):
+def test_lebesgue_normalization_value(input_dim: int):
     """Check that normalization constants are handled properly when not equal to one."""
     domain = (0, 2)
-    measure = LebesgueMeasure(domain=domain, input_dim=input_dim, normalized=True)
 
+    # normalized
+    measure = LebesgueMeasure(domain=domain, input_dim=input_dim, normalized=True)
     volume = 2**input_dim
-    assert measure.normalization_constant == 1 / volume
-
+    assert measure.normalization_constant == 1.0 / volume
 
-@pytest.mark.parametrize("domain", [(0, np.Inf), (-np.Inf, 0), (-np.Inf, np.Inf)])
-def test_lebesgue_normalization_raises(domain, input_dim: int):
-    """Check that exception is raised when normalization is not possible."""
-    with pytest.raises(ValueError):
-        LebesgueMeasure(domain=domain, input_dim=input_dim, normalized=True)
+    # not normalized
+    measure = LebesgueMeasure(domain=domain, input_dim=input_dim, normalized=False)
+    assert measure.normalization_constant == 1.0
 
 
-def test_lebesgue_unnormalized(input_dim: int):
+def test_lebesgue_normalization_value_unnormalized(input_dim: int):
     """Check that normalization constants are handled properly when equal to one."""
     measure1 = LebesgueMeasure(domain=(0, 1), input_dim=input_dim, normalized=True)
     measure2 = LebesgueMeasure(domain=(0, 1), input_dim=input_dim, normalized=False)
+
+    assert measure1.normalized
+    assert not measure2.normalized
     assert measure1.normalization_constant == measure2.normalization_constant
 
 
-# Tests for all integration measures
-def test_density_call(x, measure):
-    expected_shape = (x.shape[0],)
-    assert measure(x).shape == expected_shape
+@pytest.mark.parametrize("wrong_input_dim", [-5, -1, 0])
+def test_lebesgue_non_positive_input_dim_raises(wrong_input_dim):
+    # non positive input dimenions are not allowed
+    with pytest.raises(ValueError):
+        LebesgueMeasure(input_dim=wrong_input_dim, domain=(0, 1))
+
+
+@pytest.mark.parametrize(
+    "domain",
+    [
+        (0.0, np.ones(4)),
+        (np.ones(4), 0.0),
+        (np.zeros(4), np.ones(3)),
+        (np.zeros([4, 1]), np.ones(4)),
+        (np.zeros(4), np.ones([4, 1])),
+        (np.zeros([4, 1]), np.ones([4, 1])),
+    ],
+)
+def test_lebesgue_domain_shape_mismatch_raises(domain):
+    # left and right bounds of domain are not consistent
+    with pytest.raises(ValueError):
+        LebesgueMeasure(domain=domain)
+
+
+@pytest.mark.parametrize(
+    "input_dim,domain",
+    [
+        (1, (np.zeros(3), np.ones(3))),
+        (2, (np.zeros(3), np.ones(3))),
+        (5, (np.zeros(3), np.ones(3))),
+    ],
+)
+def test_lebesgue_domain_input_dim_mismatch_raises(input_dim, domain):
+    # input dimension does not agree with domain shapes
+    with pytest.raises(ValueError):
+        LebesgueMeasure(input_dim=input_dim, domain=domain)
+
+
+@pytest.mark.parametrize("domain", [(0, np.Inf), (-np.Inf, 0), (-np.Inf, np.Inf)])
+def test_lebesgue_normalization_raises(domain, input_dim: int):
+    """Check that exception is raised when normalization is not possible."""
+    with pytest.raises(ValueError):
+        LebesgueMeasure(domain=domain, input_dim=input_dim, normalized=True)