Re: Rounding??

Morten Welinder wrote:

   Certainly but when you provide a mapping from one space (binary) to the
   display space (decimal) is important that the display understands its
(numeric) context.
Users expect it, but it is not possible.

An accountant will want "0.365" rounded to "0.36".  A mathematician
will want "0.37".  Someone is not going to like the result.  The
mathematician also wants "=sin(pi/4)-cos(pi/4)" to yield zero.  Don't
count on it.

The mathematician also knows that computers don't use real numbers and is therefore not expecting this to be zero!

Right now we are consistent in the best-approximation sense[*], I
hope.  And no-one is happy, because -- as you say -- people generally
do not think in binary.

See the 0.62 release notes in your NEWS file for more information.


[*] The value of every subexpression is "rounded" to nearest valid
    binary representable value.

But this is distinctfrom the expected formatting behaviour!


Prof. Dr. Andreas J. Guelzow Chair of Science
Concordia University College of Alberta

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