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rhettinger · Aug 8, 2023 · 87ed56a · 87ed56a
1 parent 22f151e
commit 87ed56a
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/Lib/statistics.py b/Lib/statistics.py
@@ -1006,6 +1006,8 @@ def _mean_stdev(data):
 
 def _sqrtprod(x: float, y: float) -> float:
  "Return sqrt(x * y) computed with high accuracy."
+ # Square root differential correction:
+ # https://www.wolframalpha.com/input/?i=Maclaurin+series+sqrt%28h**2+%2B+x%29+at+x%3D0
  h = sqrt(x * y)
  x = sumprod((x, h), (y, -h))
  return h + x / (2.0 * h)