[docs] [issue37454] Clarify docs for math.log1p()

[Raymond Hettinger]

New submission from Raymond Hettinger <raymond.hettinger at gmail.com>:

Currently the docs say, "The result is calculated in a way which is accurate for x near zero."

That is somewhat vague.  Some quick tests show that it is often more accurate than log() for the whole range of 0.0 < x < 1.0; however, for x < 0.0 it is always worse.

Since the function is just a pass-through to the C library, we probably can't make any guarantees.  On the other hand, it is hard to know when this function is preferred without some guidance.

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assignee: docs at python
components: Documentation
files: study_log1p.py
messages: 346942
nosy: docs at python, mark.dickinson, rhettinger, tim.peters
priority: low
severity: normal
status: open
title: Clarify docs for math.log1p()
versions: Python 3.8, Python 3.9
Added file: https://bugs.python.org/file48448/study_log1p.py

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<https://bugs.python.org/issue37454>
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