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authorMarten van Kerkwijk <mhvk@astro.utoronto.ca>2017-12-10 14:32:40 -0500
committerMarten van Kerkwijk <mhvk@astro.utoronto.ca>2019-01-03 17:33:07 -0500
commit5afe650403bdb3aa1a3189c1b8c3233501208521 (patch)
tree224d819ab8a7d2e80a460648f1e8cb231bd4d237 /doc
parentfd89a4137969b676d4449e2b61ecd7f4c5811d7a (diff)
downloadnumpy-5afe650403bdb3aa1a3189c1b8c3233501208521.tar.gz
ENH: allow where in reduce operations.
In this implementation, if the ufunc does not have an identity, it needs an initial vavlue to be supplied.
Diffstat (limited to 'doc')
-rw-r--r--doc/release/1.17.0-notes.rst9
1 files changed, 9 insertions, 0 deletions
diff --git a/doc/release/1.17.0-notes.rst b/doc/release/1.17.0-notes.rst
index 5750ef016..c97f9a58e 100644
--- a/doc/release/1.17.0-notes.rst
+++ b/doc/release/1.17.0-notes.rst
@@ -35,6 +35,15 @@ C API changes
New Features
============
+``np.ufunc.reduce`` and related functions now accept a ``where`` mask
+---------------------------------------------------------------------
+``np.ufunc.reduce``, ``np.sum``, ``np.prod``, ``np.min``, ``np.max`` all
+now accept a ``where`` keyword argument, which can be used to tell which
+elements to include in the reduction. For reductions that do not have an
+identity, it is necessary to also pass in an initial value (e.g.,
+``initial=np.inf`` for ``np.min``). For instance, the equivalent of
+``nansum`` would be, ``np.sum(a, where=~np.isnan(a))``.
+
Improvements
============