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