Raymond Hettinger <[email protected]> added the comment:
Perhaps this would work:
diff --git a/Lib/statistics.py b/Lib/statistics.py
index c76a6ca519..93a4633464 100644
--- a/Lib/statistics.py
+++ b/Lib/statistics.py
@@ -682,8 +682,10 @@ def _ss(data, c=None):
calculated from ``c`` as given. Use the second case with care, as it can
lead to garbage results.
"""
- if c is None:
- c = mean(data)
+ if c is not None:
+ T, total, count = _sum((x-c)**2 for x in data)
+ return (T, total)
+ c = mean(data)
T, total, count = _sum((x-c)**2 for x in data)
# The following sum should mathematically equal zero, but due to rounding
# error may not.
Matti, where do you get 0.5 as the expected outcome for the third example?
The actual mean is 1.5, so I would expect the third case to give sqrt(2)/2 or
0.707.
----------
components: +Library (Lib)
versions: +Python 3.10, Python 3.8, Python 3.9 -Python 3.6
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