DOC: linalg: Include information about scipy.linalg. (#14988)

* DOC: Add links to scipy linalg fuctions and compare numpy.linalg vs scipy.linalg.

1 files changed, 12 insertions, 0 deletions

diff --git a/doc/source/reference/routines.linalg.rst b/doc/source/reference/routines.linalg.rst
index d42e77ad8..86e168b26 100644
--- a/doc/source/reference/routines.linalg.rst
+++ b/doc/source/reference/routines.linalg.rst
@@ -18,6 +18,18 @@ or specify the processor architecture.
 .. _OpenBLAS: https://www.openblas.net/
 .. _threadpoolctl: https://github.com/joblib/threadpoolctl
 
+The SciPy library also contains a `~scipy.linalg` submodule, and there is
+overlap in the functionality provided by the SciPy and NumPy submodules.  SciPy
+contains functions not found in `numpy.linalg`, such as functions related to
+LU decomposition and the Schur decomposition, multiple ways of calculating the
+pseudoinverse, and matrix transcendentals such as the matrix logarithm.  Some
+functions that exist in both have augmented functionality in `scipy.linalg`.
+For example, `scipy.linalg.eig` can take a second matrix argument for solving
+generalized eigenvalue problems.  Some functions in NumPy, however, have more
+flexible broadcasting options.  For example, `numpy.linalg.solve` can handle
+"stacked" arrays, while `scipy.linalg.solve` accepts only a single square
+array as its first argument.
+
 .. currentmodule:: numpy
 
 Matrix and vector products