Bug in floating-point addition: is anyone else seeing this?

[Carl Banks]

On May 21, 4:56 pm, Dave Parker <davepar... at flamingthunder.com> wrote:
> On May 21, 2:44 pm, "Jerry Hill" <malaclyp... at gmail.com> wrote:
>
> > My understand is no, not if you're using IEEE floating point.
>
> Yes, that would explain it.  I assumed that Python automatically
> switched from hardware floating point to multi-precision floating
> point so that the user is guaranteed to always get correctly rounded
> results for +, -, *, and /, like Flaming Thunder gives.  Correct
> rounding and accurate results are fairly crucial to mathematical and
> scientific programming, in my opinion.

Having done much mathematical and scientific prorgamming in my day, I
would say your opinion is dead wrong.

The crucial thing is not to slow down the calculations with useless
bells and whistles.  Scientists and engineers are smart enough to use
more precision than we need, and we don't really need that much.  For
instance, the simulations I run at work all use single precision (six
decimal digits) even though double precision is allowed.


Carl Banks