Fix ReadTheDocs build

.readthedocs.yml

@@ -0,0 +1,23 @@
+# .readthedocs.yml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Build documentation in the docs/ directory with Sphinx
+sphinx:
+  configuration: doc/conf.py
+
+# Optionally build your docs in additional formats such as PDF and ePub
+formats: all
+
+# Optionally set the version of Python and requirements required to build your docs
+python:
+  install:
+    - requirements: doc/requirements.txt
+
+build:
+  os: "ubuntu-22.04"
+  tools:
+    python: "3.11"

doc/conf.py

@@ -218,6 +218,6 @@
 
 # Example configuration for intersphinx: refer to the Python standard library.
 intersphinx_mapping = {
-    "https://docs.python.org/": None,
-    "https://numpy.org/doc/stable/": None,
+    "python": ("https://docs.python.org/3", None),
+    "numpy": ("https://numpy.org/doc/stable/", None),
 }

doc/requirements.txt

@@ -0,0 +1,6 @@
+numpy
+pandas
+scikit-learn
+scipy
+sphinx
+sphinx_rtd_theme