API: make piecewise subclass safe using use zeros_like.

Subclass input of piecewise was already respected, so it seems more
logical to ensure the output is the same subclass (possibly just an
oversight that it was not done before).

1 files changed, 2 insertions, 2 deletions

diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py
index d33a0fa7d..c6db42ce4 100644
--- a/numpy/lib/function_base.py
+++ b/numpy/lib/function_base.py
@@ -8,7 +8,7 @@ import numpy as np
 import numpy.core.numeric as _nx
 from numpy.core import transpose
 from numpy.core.numeric import (
-    ones, zeros, arange, concatenate, array, asarray, asanyarray, empty,
+    ones, zeros_like, arange, concatenate, array, asarray, asanyarray, empty,
     ndarray, around, floor, ceil, take, dot, where, intp,
     integer, isscalar, absolute
     )
@@ -606,7 +606,7 @@ def piecewise(x, condlist, funclist, *args, **kw):
             .format(n, n, n+1)
         )
 
-    y = zeros(x.shape, x.dtype)
+    y = zeros_like(x)
     for cond, func in zip(condlist, funclist):
         if not isinstance(func, collections.abc.Callable):
             y[cond] = func