DOC: document use when f2py is not in the PATH

1 files changed, 13 insertions, 1 deletions

diff --git a/doc/source/f2py/usage.rst b/doc/source/f2py/usage.rst
index a6f093154..3f8a6a063 100644
--- a/doc/source/f2py/usage.rst
+++ b/doc/source/f2py/usage.rst
@@ -3,7 +3,19 @@ Using F2PY
 ===========
 
 F2PY can be used either as a command line tool ``f2py`` or as a Python
-module ``f2py2e``.
+module ``f2py2e``. While we try to install the command line tool as part
+of the numpy setup, some platforms like Windows make it difficult to
+reliably put the executable on the ``PATH``. We will refer to ``f2py``
+in this document but you may have to run it as
+
+```
+python -mnumpy.f2py
+```
+
+If you run ``f2py`` with no arguments, and the line ``numpy Version`` at the
+end matches the NumPy version printed from ``python -mnumpy.f2py``, then you
+can use the shorter version. If not, or if you cannot run ``f2py``, you should
+replace all calls to ``f2py`` here with the longer version.
 
 Command ``f2py``
 =================