pylint cleanup quad (#610)

src/probnum/quad/_bayesquad.py

@@ -8,10 +8,11 @@
 """
 
 import warnings
-from typing import Callable, Dict, Optional, Tuple, Union
+from typing import Callable, Optional, Tuple, Union
 
 import numpy as np
 
+from probnum.quad.solvers.bq_state import BQInfo
 from probnum.randprocs.kernels import Kernel
 from probnum.randvars import Normal
 from probnum.typing import FloatLike, IntLike
@@ -20,7 +21,6 @@
 from .solvers import BayesianQuadrature
 
 
-# pylint: disable=too-many-arguments, no-else-raise
 def bayesquad(
     fun: Callable,
     input_dim: int,
@@ -35,8 +35,9 @@ def bayesquad(
     rel_tol: Optional[FloatLike] = None,
     batch_size: Optional[IntLike] = 1,
     rng: Optional[np.random.Generator] = np.random.default_rng(),
-) -> Tuple[Normal, Dict]:
-    r"""Infer the solution of the uni- or multivariate integral :math:`\int_\Omega f(x) d \mu(x)`
+) -> Tuple[Normal, BQInfo]:
+    r"""Infer the solution of the uni- or multivariate integral
+    :math:`\int_\Omega f(x) d \mu(x)`
     on a hyper-rectangle :math:`\Omega = [a_1, b_1] \times \cdots \times [a_D, b_D]`.
 
     Bayesian quadrature (BQ) infers integrals of the form
@@ -47,12 +48,12 @@ def bayesquad(
     :math:`\Omega \subset \mathbb{R}^D` against a measure :math:`\mu: \mathbb{R}^D
     \mapsto \mathbb{R}`.
 
-    Bayesian quadrature methods return a probability distribution over the solution :math:`F` with
-    uncertainty arising from finite computation (here a finite number of function evaluations).
-    They start out with a random process encoding the prior belief about the function :math:`f`
-    to be integrated. Conditioned on either existing or acquired function evaluations according to a
-    policy, they update the belief on :math:`f`, which is translated into a posterior measure over
-    the integral :math:`F`.
+    Bayesian quadrature methods return a probability distribution over the solution
+    :math:`F` with uncertainty arising from finite computation (here a finite number
+    of function evaluations). They start out with a random process encoding the prior
+    belief about the function :math:`f` to be integrated. Conditioned on either existing
+    or acquired function evaluations according to a policy, they update the belief on
+    :math:`f`, which is translated into a posterior measure over the integral :math:`F`.
     See Briol et al. [1]_ for a review on Bayesian quadrature.
 
     Parameters
@@ -132,7 +133,7 @@ def bayesquad(
     if domain is not None:
         if isinstance(measure, GaussianMeasure):
             raise ValueError("GaussianMeasure cannot be used with finite bounds.")
-        elif isinstance(measure, LebesgueMeasure):
+        if isinstance(measure, LebesgueMeasure):
             warnings.warn(
                 "Both domain and a LebesgueMeasure are specified. The domain "
                 "information will be ignored."
@@ -165,7 +166,7 @@ def bayesquad_from_data(
         Tuple[Union[np.ndarray, FloatLike], Union[np.ndarray, FloatLike]]
     ] = None,
     measure: Optional[IntegrationMeasure] = None,
-) -> Tuple[Normal, Dict]:
+) -> Tuple[Normal, BQInfo]:
     r"""Infer the value of an integral from a given set of nodes and function
     evaluations.
 
@@ -219,7 +220,7 @@ def bayesquad_from_data(
     if domain is not None:
         if isinstance(measure, GaussianMeasure):
             raise ValueError("GaussianMeasure cannot be used with finite bounds.")
-        elif isinstance(measure, LebesgueMeasure):
+        if isinstance(measure, LebesgueMeasure):
             warnings.warn(
                 "Both domain and a LebesgueMeasure are specified. The domain "
                 "information will be ignored."

src/probnum/quad/kernel_embeddings/_expquad_gauss.py

@@ -8,8 +8,6 @@
 from probnum.quad._integration_measures import GaussianMeasure
 from probnum.randprocs.kernels import ExpQuad
 
-# pylint: disable=invalid-name
-
 
 def _kernel_mean_expquad_gauss(
     x: np.ndarray, kernel: ExpQuad, measure: GaussianMeasure
@@ -20,17 +18,18 @@ def _kernel_mean_expquad_gauss(
     Parameters
     ----------
     x :
-        *shape=(n_eval, input_dim)* -- n_eval locations where to evaluate the kernel mean.
+        *shape=(n_eval, input_dim)* -- n_eval locations where to evaluate the kernel
+        mean.
     kernel :
         Instance of an ExpQuad kernel.
     measure :
         Instance of a GaussianMeasure.
 
     Returns
     -------
-    k_mean :
+    kernel_mean :
         *shape (n_eval,)* -- The kernel integrated w.r.t. its first argument,
-        evaluated at locations x.
+        evaluated at locations ``x``.
     """
     input_dim = kernel.input_dim
 
@@ -66,7 +65,7 @@ def _kernel_variance_expquad_gauss(kernel: ExpQuad, measure: GaussianMeasure) ->
 
     Returns
     -------
-    k_var :
+    kernel_variance :
         The kernel integrated w.r.t. both arguments.
     """
     input_dim = kernel.input_dim

src/probnum/quad/kernel_embeddings/_expquad_lebesgue.py

@@ -1,7 +1,7 @@
 """Kernel embedding of exponentiated quadratic kernel with Lebesgue integration
 measure."""
 
-# pylint: disable=no-name-in-module, invalid-name
+# pylint: disable=no-name-in-module
 
 import numpy as np
 from scipy.special import erf
@@ -19,17 +19,18 @@ def _kernel_mean_expquad_lebesgue(
     Parameters
     ----------
     x :
-        *shape (n_eval, input_dim)* -- n_eval locations where to evaluate the kernel mean.
+        *shape (n_eval, input_dim)* -- n_eval locations where to evaluate the kernel
+        mean.
     kernel :
         Instance of an ExpQuad kernel.
     measure :
         Instance of a LebesgueMeasure.
 
     Returns
     -------
-    k_mean :
+    kernel_mean :
         *shape=(n_eval,)* -- The kernel integrated w.r.t. its first argument,
-        evaluated at locations x.
+        evaluated at locations ``x``.
     """
     input_dim = kernel.input_dim
 
@@ -59,7 +60,7 @@ def _kernel_variance_expquad_lebesgue(
 
     Returns
     -------
-    k_var :
+    kernel_variance :
         The kernel integrated w.r.t. both arguments.
     """
 

src/probnum/quad/kernel_embeddings/_kernel_embedding.py

@@ -27,6 +27,12 @@ class KernelEmbedding:
         Instance of a kernel.
     measure:
         Instance of an integration measure.
+
+    Raises
+    ------
+    ValueError
+        If the input dimension of the kernel does not match the input dimension of the
+        measure.
     """
 
     def __init__(self, kernel: Kernel, measure: IntegrationMeasure) -> None:
@@ -45,20 +51,20 @@ def __init__(self, kernel: Kernel, measure: IntegrationMeasure) -> None:
             kernel=self.kernel, measure=self.measure
         )
 
-    # pylint: disable=invalid-name
     def kernel_mean(self, x: np.ndarray) -> np.ndarray:
         """Kernel mean w.r.t. its first argument against the integration measure.
 
         Parameters
         ----------
         x :
-            *shape=(n_eval, input_dim)* -- n_eval locations where to evaluate the kernel mean.
+            *shape=(n_eval, input_dim)* -- n_eval locations where to evaluate the
+            kernel mean.
 
         Returns
         -------
-        k_mean :
+        kernel_mean :
             *shape=(n_eval,)* -- The kernel integrated w.r.t. its first argument,
-            evaluated at locations x.
+            evaluated at locations ``x``.
         """
         return self._kmean(x=x, kernel=self.kernel, measure=self.measure)
 
@@ -67,7 +73,7 @@ def kernel_variance(self) -> float:
 
         Returns
         -------
-        k_var :
+        kernel_variance :
             The kernel integrated w.r.t. both arguments.
         """
         return self._kvar(kernel=self.kernel, measure=self.measure)
@@ -87,15 +93,24 @@ def _get_kernel_embedding(
 
     Returns
     -------
-        An instance of _KernelEmbedding.
+    kernel_mean :
+        The kernel mean function.
+    kernel_variance :
+        The kernel variance function.
+
+    Raises
+    ------
+    NotImplementedError
+        If the given kernel is unknown.
+    NotImplementedError
+        If the kernel embedding of the kernel-measure pair is unknown.
     """
 
     # Exponentiated quadratic kernel
     if isinstance(kernel, ExpQuad):
-        # pylint: disable=no-else-return
         if isinstance(measure, GaussianMeasure):
             return _kernel_mean_expquad_gauss, _kernel_variance_expquad_gauss
-        elif isinstance(measure, LebesgueMeasure):
+        if isinstance(measure, LebesgueMeasure):
             return _kernel_mean_expquad_lebesgue, _kernel_variance_expquad_lebesgue
         raise NotImplementedError
 

src/probnum/quad/solvers/bayesian_quadrature.py

@@ -98,6 +98,19 @@ def from_problem(
             Batch size used in node acquisition.
         rng :
             The random number generator.
+
+        Returns
+        -------
+        BayesianQuadrature
+            An instance of this class.
+
+        Raises
+        ------
+        ValueError
+            If Bayesian Monte Carlo ('bmc') is selected as ``policy`` and no random
+            number generator (``rng``) is given.
+        NotImplementedError
+            If an unknown ``policy`` is given.
         """
         # Set up integration measure
         if measure is None:
@@ -125,8 +138,8 @@ def from_problem(
                 "Policies other than random sampling are not available at the moment."
             )
 
-        # Set stopping criteria
-        # If multiple stopping criteria are given, BQ stops once the first criterion is fulfilled.
+        # Set stopping criteria: If multiple stopping criteria are given, BQ stops
+        # once the first criterion is fulfilled.
         def _stopcrit_or(sc1, sc2):
             if sc1 is None:
                 return sc2
@@ -147,7 +160,8 @@ def _stopcrit_or(sc1, sc2):
                 _stopping_criterion, RelativeMeanChange(rel_tol)
             )
 
-        # If no stopping criteria are given, use some default values (these are arbitrary values)
+        # If no stopping criteria are given, use some default values
+        # (these are arbitrary values)
         if _stopping_criterion is None:
             _stopping_criterion = IntegralVarianceTolerance(var_tol=1e-6) | MaxNevals(
                 max_nevals=input_dim * 25
@@ -167,13 +181,13 @@ def has_converged(self, bq_state: BQState) -> bool:
         Parameters
         ----------
         bq_state:
-            State of the Bayesian quadrature methods. Contains all necessary information about the
-            problem and the computation.
+            State of the Bayesian quadrature methods. Contains all necessary
+            information about the problem and the computation.
 
         Returns
         -------
-        has_converged:
-            Whether or not the solver has converged.
+        has_converged :
+            Whether the solver has converged.
         """
 
         _has_converged = self.stopping_criterion(bq_state)
@@ -192,7 +206,8 @@ def bq_iterator(
     ) -> Tuple[Normal, np.ndarray, np.ndarray, BQState]:
         """Generator that implements the iteration of the BQ method.
 
-        This function exposes the state of the BQ method one step at a time while running the loop.
+        This function exposes the state of the BQ method one step at a time while
+        running the loop.
 
         Parameters
         ----------
@@ -208,23 +223,22 @@ def bq_iterator(
         integral_belief:
             Current belief about the integral.
         bq_state:
-            State of the Bayesian quadrature methods. Contains all necessary information about the
-            problem and the computation.
+            State of the Bayesian quadrature methods. Contains all necessary information
+            about the problem and the computation.
 
-        Returns
-        -------
-        integral_belief:
+        Yields
+        ------
+        new_integral_belief :
             Updated belief about the integral.
-        new_nodes:
+        new_nodes :
             *shape=(n_new_eval, input_dim)* -- The new location(s) at which
             ``new_fun_evals`` are available found during the iteration.
-        new_fun_evals:
+        new_fun_evals :
             *shape=(n_new_eval,)* -- The function evaluations at the new locations
             ``new_nodes``.
-        bq_state:
+        new_bq_state :
             Updated state of the Bayesian quadrature methods.
         """
-        # pylint: disable=missing-yield-doc
 
         # Setup
         if bq_state is None:
@@ -293,8 +307,9 @@ def integrate(
     ) -> Tuple[Normal, BQState]:
         """Integrate the function ``fun``.
 
-        ``fun`` may be analytically given, or numerically in terms of ``fun_evals`` at fixed nodes.
-        This function calls the generator ``bq_iterator`` until the first stopping criterion is met.
+        ``fun`` may be analytically given, or numerically in terms of ``fun_evals`` at
+        fixed nodes. This function calls the generator ``bq_iterator`` until the first
+        stopping criterion is met.
 
         Parameters
         ----------
@@ -310,10 +325,16 @@ def integrate(
 
         Returns
         -------
-        integral_belief:
+        integral_belief :
             Posterior belief about the integral.
-        bq_state:
+        bq_state :
             Final state of the Bayesian quadrature method.
+
+        Raises
+        ------
+        ValueError
+            If neither the integrand function (``fun``) nor integrand evaluations
+            (``fun_evals``) are given.
         """
         if fun is None and fun_evals is None:
             raise ValueError("You need to provide a function to be integrated!")

src/probnum/quad/solvers/belief_updates/_belief_update.py

@@ -45,7 +45,8 @@ def __call__(
         Returns
         -------
         updated_belief :
-            Gaussian integral belief after conditioning on the new nodes and evaluations.
+            Gaussian integral belief after conditioning on the new nodes and
+            evaluations.
         updated_state :
             Updated version of ``bq_state`` that contains all updated quantities.
         """
@@ -110,7 +111,7 @@ def _solve_gram(gram: np.ndarray, rhs: np.ndarray) -> np.ndarray:
 
         Returns
         -------
-        x:
+        x :
             The solution to the linear system :math:`K x = b`
         """
         jitter = 1.0e-6