On Dec 23, 12:35 ¨Âí¬ êúáëéù¼êúáë®®®Àíáéì®ãïí¾ ÷òïôåº
> Dear Matz,
>
> I use a Linux calculator named Qaculate.
> I do not know the people who designed and
> coded it, but it makes me happy. Why?
>
> When I put in sin(180) it outputs '0'
> not 1.22460635382238e-16, and when I change
> to radians for angles and do sin(PI) it
> also gives '0' and not 1.22460635382238e-16.
>
> This makes me happy.
>
> In fact, this little Linux calculator produces
> all the correct (exact) answers for angles on
> an axis for both cos and sin, whether you input
> the angles in degrees or radians. Astonishing!!
>
> I don't now anything about how the people who
> designed and implemented Qalculate decided to
> use whatever language they chose to write it in,
> or what libraries they decided to use. I don't
> know (or care) about any of those under-the-hood
> things.
>
> What I do KNOW is that the people who designed and
> implemented this calculator CARED that it produced
> the mathematically exact results for those angles.
>
> This makes me happy.
>
> I use another add-on calculator for Firefox, called,
> tada! Calculator. Again, I don't know the people who
> designed and/or coded it, and I don't know what
> language or libraries they used to do it in either.
> But when I use this little calculator in Firefox I do
> know I get sin(PI) = 0, not 1.22460635382238e-16.
>
> So, for this calculator too, somebody(s) CARED enough
> to make sure the answers came out correctly (exact)
> for angles on an axis too. So when I use this calculator,
>
> This makes me happy.
>
> I think Ruby is a Great language, and a fun language.
> And I agree with your philosophy that languages that
> people use should serve them, not the other way around.
>
> So I humbly tell you I am Surprised that Ruby produces
> the math errors I've illustrated in this thread, and
>
> This makes me unhappy.
>
> So I am asking you to see that these errors be fixed.
>
> If Qaculator and Calculator can produce the correct
> results, then so can Ruby. All that is necessary is that
> you CARE enough that it does it.
>
> It would make me very happy if I could share my code, and
> not have to include patches and redefinitions in it just
> to assure other people get the same (exact) results I do.
>
> I agree with your Principle of Least Surprises (POLS).
>
> The language should work to please the user.
> The language should be intuitive to the user.
> The language should not cause unnecessary surprises.
>
> So please, fix these errors.
>
> This will make me happy.
>
> Thanks

Also, as an example:

static VALUE
math_cos(VALUE obj, VALUE x)
{
    Need_Float(x);
    return DBL2NUM(cos(RFLOAT_VALUE(x)));
}

If you have a beef with anyone, its with the implementers of the C
standard library, but...