[Haskell-beginners] How to improve the accuracy of floating point calculation?

[Darren Grant]

I'm not sure how CReal implements its values, but IEEE754 also supports
decimal formats preferred for accuracy in many applications. Take a look:

   http://en.wikipedia.org/wiki/IEEE_floating_point


Cheers,
d




On Tue, Feb 5, 2013 at 3:24 PM, Patrick Mylund Nielsen <
haskell at patrickmylund.com> wrote:

> http://floating-point-gui.de/
> http://floating-point-gui.de/formats/fp/
>
> http://en.wikipedia.org/wiki/Floating_point#Accuracy_problems
>
>
> On Wed, Feb 6, 2013 at 12:08 AM, KC <kc1956 at gmail.com> wrote:
>
>> 0.1 cannot be represented exactly in floating point.
>>
>> 0.5 can be represented exactly.  Why?
>>
>>
>> On Tue, Feb 5, 2013 at 2:41 PM, yi lu <zhiwudazhanjiangshi at gmail.com>
>> wrote:
>> > Hi,
>> >
>> > I found that in ghci, I input
>> > [0.1,0.2..2]
>> > and run, I get a result of
>> >
>> >
>> [0.1,0.2,0.30000000000000004,0.4000000000000001,0.5000000000000001,0.6000000000000001,0.7000000000000001,0.8,0.9,1.0,1.1,1.2000000000000002,1.3000000000000003,1.4000000000000004,1.5000000000000004,1.6000000000000005,1.7000000000000006,1.8000000000000007,1.9000000000000008,2.000000000000001]
>> >
>> > But, as you know, it is not the exact answer.
>> >
>> > So, I wonder if there is something I can do to achieve a better
>> performance
>> > and get [0.1,0.2,0.3,0.4..] as the result.
>> >
>> > Thanks.
>> >
>> > _______________________________________________
>> > Beginners mailing list
>> > Beginners at haskell.org
>> > http://www.haskell.org/mailman/listinfo/beginners
>> >
>>
>>
>>
>> --
>> --
>> Regards,
>> KC
>>
>> _______________________________________________
>> Beginners mailing list
>> Beginners at haskell.org
>> http://www.haskell.org/mailman/listinfo/beginners
>>
>
>
> _______________________________________________
> Beginners mailing list
> Beginners at haskell.org
> http://www.haskell.org/mailman/listinfo/beginners
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/beginners/attachments/20130205/1947037c/attachment.htm>