[Haskell-cafe] Re: Simple quirk in behavior of `mod`

[Andy Gimblett]

On 23 Jul 2009, at 11:59, Matthias Görgens wrote:

>> Round-to-even means x.5 gets rounded to x if x is even and x+1 if x  
>> is
>> odd. This is sometimes known as banker's rounding.
>
> OK.  That's slightly unusual indeed.

It's meant to minimise total rounding error when rounding over large  
data sets; there's some discussion on wikipedia: http://en.wikipedia.org/wiki/Rounding