Document several optional dependencies of knn

1 files changed, 28 insertions, 0 deletions

diff --git a/src/python/doc/installation.rst b/src/python/doc/installation.rst
index 48425d5e..09a843d5 100644
--- a/src/python/doc/installation.rst
+++ b/src/python/doc/installation.rst
@@ -211,6 +211,14 @@ The following examples requires CGAL version ≥ 4.11.0:
     * :download:`euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py <../example/euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py>`
     * :download:`euclidean_witness_complex_diagram_persistence_from_off_file_example.py <../example/euclidean_witness_complex_diagram_persistence_from_off_file_example.py>`
 
+EagerPy
+=======
+
+Some Python functions can handle automatic differentiation (possibly only when
+a flag `enable_autodiff=True` is used). In order to reduce code duplication, we
+use `EagerPy <https://eagerpy.jonasrauber.de/>`_ which wraps arrays from
+PyTorch, TensorFlow and JAX in a common interface.
+
 Eigen
 =====
 
@@ -229,6 +237,13 @@ The following examples require `Eigen <http://eigen.tuxfamily.org/>`_ version â‰
     * :download:`euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py <../example/euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py>`
     * :download:`euclidean_witness_complex_diagram_persistence_from_off_file_example.py <../example/euclidean_witness_complex_diagram_persistence_from_off_file_example.py>`
 
+Hnswlib
+=======
+
+:class:`~gudhi.point_cloud.knn.KNearestNeighbors` can use the Python package
+`Hnswlib <https://github.com/nmslib/hnswlib>`_ as a backend if explicitly
+requested, to speed-up queries.
+
 Matplotlib
 ==========
 
@@ -251,6 +266,13 @@ The following examples require the `Matplotlib <http://matplotlib.org>`_:
     * :download:`euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py <../example/euclidean_strong_witness_complex_diagram_persistence_from_off_file_example.py>`
     * :download:`euclidean_witness_complex_diagram_persistence_from_off_file_example.py <../example/euclidean_witness_complex_diagram_persistence_from_off_file_example.py>`
 
+PyKeOps
+=======
+
+:class:`~gudhi.point_cloud.knn.KNearestNeighbors` can use the Python package
+`PyKeOps <https://www.kernel-operations.io/keops/python/>`_ as a backend if
+explicitly requested, to speed-up queries using a GPU.
+
 Python Optimal Transport
 ========================
 
@@ -258,6 +280,12 @@ The :doc:`Wasserstein distance </wasserstein_distance_user>`
 module requires `POT <https://pot.readthedocs.io/>`_, a library that provides
 several solvers for optimization problems related to Optimal Transport.
 
+PyTorch
+=======
+
+`PyTorch <https://pytorch.org/>`_ is currently only used as a dependency of
+`PyKeOps`_, and in some tests.
+
 Scikit-learn
 ============