From: Mohamed Iguernlala <iguer.auto@gmail.com>
To: Xavier Leroy <xavier.leroy@inria.fr>, caml-list@inria.fr
Subject: Re: [Caml-list] Is this a bug in Num.float_of_num ?
Date: Thu, 26 May 2016 11:16:18 +0200 [thread overview]
Message-ID: <5746BEE2.3020907@gmail.com> (raw)
In-Reply-To: <5746BA85.4030100@inria.fr>
Le 26/05/2016 10:57, Xavier Leroy a écrit :
> On 26/05/2016 10:24, Mohamed Iguernlala wrote:
>> Hi,
>>
>> I came to the following "stange" behavior when using the function
>> float_of_num. I don't know if this should be considered as a bug,
>> since this function has no specification (in num.mli *)
>>
>> The float "f = 6004799503160661. /. 18014398509481984." has an
>> exact representation on 64 bits. Its value is
>>
>> 0.333333333333333314829616256247390992939472198486328125
>>
>> However, when using float_of_num to compute the float corresponding to
>> the number above represented as a num, the result is slightly different.
> float_of_ratio and float_of_num are very imprecise in OCaml 4.02 and
> earlier. They were reimplemented in OCaml 4.03 in a way that should
> give correct roundings. So, make sure you're using 4.03, and if the
> bug is still there, please file a report on Mantis.
Thanks, the result is correct with OCaml 4.03.0.
I hadn't tried before because the constant "let floating_precision = ref 12"
is still there in OCaml 4.03.0 ... Sorry.
Regards,
Mohamed.
prev parent reply other threads:[~2016-05-26 9:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-26 8:24 Mohamed Iguernlala
2016-05-26 8:57 ` Xavier Leroy
2016-05-26 9:16 ` Mohamed Iguernlala [this message]
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