Decide on fate of missing C23 math.h functions
Nobody has claimed this yet.
- Dominant language
- Python
- Stars
- 77.2k
- Forks
- 35.9k
- PR merge metrics
- PR metrics pending
Description
Feature or enhancement
Proposal:
With https://github.com/python/cpython/issues/150534 it seems that sinpi et all will be landed in the math module. Lets discuss here remaining functions, coming with C23:
- exp10 - The exp10 functions compute the base-10 exponential of x.
- exp2m1 - The exp2m1 functions compute the base-2 exponential of the argument, minus 1.
- exp10m1 - The exp10m1 functions compute the base-10 exponential of the argument, minus 1.
- log2p1 - The log2p1 functions compute the base-2 logarithm of 1 plus the argument.
- log10p1 - The log10p1 functions compute the base-10 logarithm of 1 plus the argument.
- logp1 - alias of log1p, should we consider renaming?
- rootn - The rootn functions compute the principal nth root of x.
- rsqrt - The rsqrt functions compute the reciprocal of the nonnegative square root of the argument.
For completeness, cases that can change semantics of pow():
- pown - The pown functions compute x raised to the nth power.
- powr - The powr functions compute x raised to the power y as
e**(y*log(x)).
References:
- n1946.pdf
- C23 standard
CC @picnixz, @rhettinger, @tim-one
I think that missing exp/log functions are good addition on same ground, as existing functions. log1p can be soft-deprecated (I don't think it worth considering deviations in naming like log1p2 and log1p10). I'm less certain about rootn (seems useful, but I would prefer rather some cmath function, that can return any k-th from n roots) and rsqrt.
Consider this as a continuation of https://github.com/python/cpython/issues/135853.
Has this already been discussed elsewhere?
No response given
Links to previous discussion of this feature:
No response
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reading the Python math module context and the C23 references linked in the issue, then review the continuation issue #135853 and the discussion in #150534. The work is not yet implementation-ready: done means reaching a decision about which listed functions, naming changes, or semantic changes Python should adopt.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- c, python
- Domain
- api, backend
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Quiet
- Clarity
- Needs clarification
- Newbie friendliness
- 28/100