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Re: use of math.h / libmath discouraged?
From: |
Paul Smith |
Subject: |
Re: use of math.h / libmath discouraged? |
Date: |
Wed, 25 Jul 2018 09:06:05 -0400 |
On Tue, 2018-07-24 at 16:04 -0600, Brian Vandenberg wrote:
> In a plugin I wrote I created a function with the following form /
> function:
>
> $ cat makefile
> ASDF := something
> $(timeit 100, ${ASDF})
> $ make
> makefile:2 Time taken: mean: 232, stdev: 81.719765
>
> make: *** No targets. Stop.
>
> ... where "timeit" is implemented using the online mean/variance
> estimate from Knuth's TAoCP. It evaluates the 2nd argument a number
> of times equal to what the 1st argument evaluates to then spits out a
> mean / std deviation across those runs.
>
> I want to contribute this function back to the make project, however
> there's a problem if it gets accepted: calculating the standard
> deviation requires calling sqrt from math.h / libmath.
>
> Am I safe to assume that adding a dependence on math.h / libmath
> isn't an option?
IIRC, math.h / sqrt() is defined in the ISO C90 standard and so it
should be portable.
However, I'm not sure that this function is sufficiently generic to be
added as a built-in function. Can you provide use-cases for it?
Cheers!