New submission from Raymond Hettinger <raymond.hettin...@gmail.com>:
A need for a distance-between-two-points function arises frequently enough to
warrant consideration for inclusion in the math module. It shows-up
throughout mathematics -- everywhere from simple homework problems for kids to
machine learning and computer vision.
In the latter cases, the function is called frequently and would benefit from a
fast C implementation that includes good error checking and is algorithmically
smart about numerical issues such as overflow and loss-of-precision.
A simple implementation would be something like this:
def dist(p, q):
'Multi-dimensional Euclidean distance'
# XXX needs error checking: len(p) == len(q)
return sqrt(sum((x0 - x1) ** 2 for x0, x1 in zip(p, q)))
The implementation could also include value added features such as hypot()
style scaling to mitigate overflow during the squaring step:
def dist2(p, q):
# https://en.wikipedia.org/wiki/Hypot#Implementation
diffs = [x0 - x1 for x0, x1 in zip(p, q)]
scale = max(diffs, key=abs)
return abs(scale) * sqrt(fsum((d/scale) ** 2 for d in diffs))
----------
components: Library (Lib)
messages: 313967
nosy: mark.dickinson, rhettinger, skrah, steven.daprano, tim.peters
priority: normal
severity: normal
status: open
title: Add multi-dimensional Euclidean distance function to the math module
type: enhancement
versions: Python 3.8
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Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue33089>
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