It is certainly what I learnt in school. But that was another school.
On Mon, Oct 27, 2008 at 12:15 PM, Janis Voigtlaender <[EMAIL PROTECTED]> wrote: > Henning Thielemann wrote: >> >> On Mon, 27 Oct 2008, L.Guo wrote: >> >>> I think this is unresonable. then try it in GHC 6.8.3. >>> >>> >>> Prelude> round 3.5 >>> 4 >>> Prelude> round 2.5 >>> 2 >>> >>> >>> Is there any explanation about that ? >> >> >> It's the definition we learnt in school ... > > Hmm, Henning, this is strange. The two of us went to the very same > school, but I know for a fact that I learnt 2.5 to round to 3, not 2 as > above. ;-) > >> I think one reason is that repeated rounding should not be worse than >> rounding in one go. Consider the rule 'use ceiling when the first removed >> digit is 5'. Then >> >> 0.45 - (round to one place) -> 0.5 - (round to integer) -> 1 >> >> but >> >> 0.45 - (round to integer) -> 0 > > That is of course true (and was the topic of heated discussion with my > fourth grade math teacher), but does not explain 2.5 -> 2. > > Ciao, Janis. > > -- > Dr. Janis Voigtlaender > http://wwwtcs.inf.tu-dresden.de/~voigt/ > mailto:[EMAIL PROTECTED] > > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe > _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
