[Haskell-cafe] Why 'round' does not just round numbers ?

[Henning Thielemann]

On Mon, 27 Oct 2008, Janis Voigtlaender wrote:

> Lennart Augustsson wrote:
>> I can't remember the method being called anything.
>> It was just what we were being taught.  With the obvious explanation
>> that .5 is right in the middle so always going one way would introduce
>> a bias.  This was circa 1969.
>
> Well, I wasn't serious about the "political" explanation.
>
> And yes, the "avoiding bias" explanation makes sense, but not the "this
> way of rounding makes repeated rounding safe" explanation.

In measured data the .5-case should be very rare - a "null set"? However I 
assume that .5 happens more often in practice - because of prior rounding, 
which was shown to be bad practice in this thread. :-)