[New-bugs-announce] [issue45917] Add math.exp2() function: 2^x

[Gideon]

New submission from Gideon <gideonmitchell01 at gmail.com>:

Dear Python Support Team,

I was looking through Python’s list of supported methods in the math module, and I noticed that C99’s exp2 method was not implemented. This method raises 2 to the power of the supplied argument. I understand that it’s pretty trivial to so this in Python using 2**x or math.pow(x, 2), but I think there are a few reasons why we might want to incorporate it:

Uniformity: This method exists most other programming languages and libraries, including numpy.

Consistency: Every math method from C99 except exp2 is in python’s math or cmath module (math.cbrt will be added as of python 3.11).

Triviality: this method is a part of C99 and is also supported by Visual Studio, so it’s very easy to implement. 

Accuracy(?): a libm exp2 is supposedly more accurate than pow(2.0, x), though I don’t really see how this would be the case (See https://bugs.python.org/issue31980)


That said, this method is a little redundant, so I completely understand if this request is rejected

Non-exhaustive list of other languages / libraries that use this method:

Rust: https://docs.rs/libm/0.1.1/libm/fn.exp2.html
Javascript: https://github.com/stdlib-js/math-base-special-exp2
Numpy: https://numpy.org/doc/stable/reference/generated/numpy.exp2.html
C++: https://en.cppreference.com/w/cpp/numeric/math/exp2 (Not authoritative)
Ruby: https://www.rubydoc.info/gems/ruby-mpfi/MPFI%2FMath.exp2

Similar Issues:
https://bugs.python.org/issue44357
https://bugs.python.org/issue31980

----------
components: Library (Lib)
messages: 407214
nosy: Gideon
priority: normal
severity: normal
status: open
title: Add math.exp2() function: 2^x
type: enhancement
versions: Python 3.11

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue45917>
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