scikit-learn · glemaitre · Dec 1, 2023 · Oct 25, 2023 · Oct 30, 2023 · Oct 30, 2023
diff --git a/doc/whats_new/v1.4.rst b/doc/whats_new/v1.4.rst
@@ -236,6 +236,12 @@ Changelog
 :mod:`sklearn.cluster`
 ......................
 
+- |Fix| The `degree` parameter in the :class:`cluster.SpectralClustering`
+  constructor now accepts real values instead of only integral values in
+  accordance with the `degree` parameter of the
+  :class:`sklearn.metrics.pairwise.polynomial_kernel`. :pr:`27668` by
+  :user:`Nolan McMahon <NolantheNerd>`.
+
 - |API| `kdtree` and `balltree` values are now deprecated and are renamed as
   `kd_tree` and `ball_tree` respectively for the `algorithm` parameter of
   :class:`cluster.HDBSCAN` ensuring consistency in naming convention.
@@ -304,6 +310,12 @@ Changelog
 - |Fix| :func:`decomposition.dict_learning_online` does not ignore anymore the parameter
   `max_iter`.
   :pr:`27834` by :user:`Guillaume Lemaitre <glemaitre>`.
+
+- |Fix| The `degree` parameter in the :class:`decomposition.KernelPCA`
+  constructor now accepts real values instead of only integral values in
+  accordance with the `degree` parameter of the
+  :class:`sklearn.metrics.pairwise.polynomial_kernel`. :pr:`27668` by
+  :user:`Nolan McMahon <NolantheNerd>`.
 
 - |API| The option `max_iter=None` in
   :class:`decomposition.MiniBatchDictionaryLearning`,
@@ -398,6 +410,16 @@ Changelog
   of a `ValueError` when an estimator does not implement the requested response method.
   :pr:`27291` by :user:`Guillaume Lemaitre <glemaitre>`.
 
+:mod:`sklearn.kernel_ridge`
+...........................
+
+- |Fix| The `degree` parameter in the :class:`kernel_ridge.KernelRidge`
+  constructor now accepts real values instead of only integral values in
+  accordance with the `degree` parameter of the
+  :class:`sklearn.metrics.pairwise.polynomial_kernel`. :pr:`27668` by
+  :user:`Nolan McMahon <NolantheNerd>`.
+
+
 :mod:`sklearn.linear_model`
 ...........................
 

diff --git a/sklearn/cluster/_spectral.py b/sklearn/cluster/_spectral.py
@@ -609,7 +609,7 @@ class SpectralClustering(ClusterMixin, BaseEstimator):
             StrOptions({"auto"}),
         ],
         "assign_labels": [StrOptions({"kmeans", "discretize", "cluster_qr"})],
-        "degree": [Interval(Integral, 0, None, closed="left")],
+        "degree": [Interval(Real, 0, None, closed="left")],
         "coef0": [Interval(Real, None, None, closed="neither")],
         "kernel_params": [dict, None],
         "n_jobs": [Integral, None],

diff --git a/sklearn/decomposition/_kernel_pca.py b/sklearn/decomposition/_kernel_pca.py
@@ -56,7 +56,7 @@ class KernelPCA(ClassNamePrefixFeaturesOutMixin, TransformerMixin, BaseEstimator
         Kernel coefficient for rbf, poly and sigmoid kernels. Ignored by other
         kernels. If ``gamma`` is ``None``, then it is set to ``1/n_features``.
 
-    degree : int, default=3
+    degree : float, default=3
         Degree for poly kernels. Ignored by other kernels.
 
     coef0 : float, default=1
@@ -251,7 +251,7 @@ class KernelPCA(ClassNamePrefixFeaturesOutMixin, TransformerMixin, BaseEstimator
             Interval(Real, 0, None, closed="left"),
             None,
         ],
-        "degree": [Interval(Integral, 0, None, closed="left")],
+        "degree": [Interval(Real, 0, None, closed="left")],
         "coef0": [Interval(Real, None, None, closed="neither")],
         "kernel_params": [dict, None],
         "alpha": [Interval(Real, 0, None, closed="left")],

diff --git a/sklearn/kernel_ridge.py b/sklearn/kernel_ridge.py
@@ -3,7 +3,7 @@
 # Authors: Mathieu Blondel <[email protected]>
 #          Jan Hendrik Metzen <[email protected]>
 # License: BSD 3 clause
-from numbers import Integral, Real
+from numbers import Real
 
 import numpy as np
 
@@ -69,7 +69,7 @@ class KernelRidge(MultiOutputMixin, RegressorMixin, BaseEstimator):
         the kernel; see the documentation for sklearn.metrics.pairwise.
         Ignored by other kernels.
 
-    degree : int, default=3
+    degree : float, default=3
         Degree of the polynomial kernel. Ignored by other kernels.
 
     coef0 : float, default=1
@@ -138,7 +138,7 @@ class KernelRidge(MultiOutputMixin, RegressorMixin, BaseEstimator):
             callable,
         ],
         "gamma": [Interval(Real, 0, None, closed="left"), None],
-        "degree": [Interval(Integral, 0, None, closed="left")],
+        "degree": [Interval(Real, 0, None, closed="left")],
         "coef0": [Interval(Real, None, None, closed="neither")],
         "kernel_params": [dict, None],
     }