Re: mathlib

[Roberto Ierusalimschy <roberto@...>]

> I have been following this discusson with a growing interest, and I would
> just like to humbly share my point on the topic.
> My major is hydraulics. I am using Lua to write simple applications / demos
> / various implementations to illustrate fluid dynamics concepts when
> teaching students.  Although hyperbolic functions do not seem to be widely
> used in general, they are used a lot in my field, especially when it comes
> to study flow field, divergence, circulation, etc. And I am pretty much
> convinced that, out there, even in games, hyperbolic function can be
> useful, moreover if one wants to model physically-accurate phenomenons.

No one should question this.  Out there, *everything* is useful to some
people. If we are going to add to Lua everything that can be useful to
some groups, we will easily outgrow Common Lisp.


> That said, I won't be bothered that much if those functions were removed.
> After all, I can quickly implemented them using those algebraic
> equivalence[1], or use Taylor Series expansion[2]. But being forced to do
> that would be a bit repetitive, and boring. And no, I would not appreciate
> that much having to require an external module to access to some feature I
> already know how to implement by myself.

Note that the "official" alternative would not be to implement your
own functions, but simply to use an external library, such as mathx.
With that library you will have not only sinh, cosh, and tanh, but
also their inverses plus 32 other useful mathematical functions not
present in mathlib.

-- Roberto