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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: routine for angles needed |
| Date | 2015-08-03 18:30 -0700 |
| Organization | None to speak of |
| Message-ID | <lnpp33hmck.fsf@kst-u.example.com> (permalink) |
| References | (12 earlier) <16138ae3-5e39-4347-8d0a-4a82bbdf0f8c@googlegroups.com> <ca0e8c9e-cff4-431c-aab9-65a4b29e2435@googlegroups.com> <mpo5tl$2kj$1@dont-email.me> <lntwsggkzc.fsf@kst-u.example.com> <mpor76$sj9$1@dont-email.me> |
Bartc <bc@freeuk.com> writes:
> On 03/08/2015 21:44, Keith Thompson wrote:
>> Bartc <bc@freeuk.com> writes:
>> [...]
>>> C uses binary floating point.
>> [...]
>>
>> Most (probably nearly all) C implementations use binary floating-point.
>> The standard permits other bases, which is why FLT_RADIX exists.
>>
>> Some IBM mainframe systems use base 16 -- which has most of the
>> characteristics of binary, but the precision fluctuates more depending
>> on the exponent value. Base 10 floating-point is not unheard of.
>
> Using that knowledge, that there might be systems for which C doesn't
> use binary FP, would you be able to say that fmod(9.0,3.33) gives
> exactly 2.34?
>
> Probably not... Certainly you couldn't rely on it.
Certainly not. On my system it yields
2.339999999999999857891452847979962825775146484375
or equivalently
0x1.2b851eb851eb8p+1
On a system where FLT_RADIX == 10 (or is a power of 10), fmod(9.0, 3.33)
probably would be exactly 2.34.
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 10:17 -0700
Re: routine for angles needed Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-08-02 10:38 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 11:10 -0700
Re: routine for angles needed Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-08-02 11:26 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 11:41 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 12:02 -0700
Re: routine for angles needed Bartc <bc@freeuk.com> - 2015-08-02 18:41 +0100
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 11:43 -0700
Re: routine for angles needed Bartc <bc@freeuk.com> - 2015-08-02 20:00 +0100
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 12:04 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 12:10 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 12:24 -0700
Re: routine for angles needed Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-08-02 12:32 -0700
Re: routine for angles needed Bartc <bc@freeuk.com> - 2015-08-02 20:40 +0100
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 12:59 -0700
Re: routine for angles needed Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-08-02 13:14 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 13:39 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 13:45 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-03 07:48 -0700
Re: routine for angles needed Bartc <bc@freeuk.com> - 2015-08-03 17:06 +0100
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-03 09:09 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-03 09:17 -0700
Re: routine for angles needed Bartc <bc@freeuk.com> - 2015-08-03 17:48 +0100
Re: routine for angles needed Keith Thompson <kst-u@mib.org> - 2015-08-03 13:44 -0700
Re: routine for angles needed Bartc <bc@freeuk.com> - 2015-08-03 23:51 +0100
Re: routine for angles needed Keith Thompson <kst-u@mib.org> - 2015-08-03 18:30 -0700
Re: routine for angles needed glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-03 23:11 +0000
Re: routine for angles needed Bartc <bc@freeuk.com> - 2015-08-04 01:32 +0100
Re: routine for angles needed glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-04 01:14 +0000
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-08-03 20:26 -0500
Re: routine for angles needed glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-04 18:24 +0000
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-08-05 01:46 -0500
Re: routine for angles needed glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-05 18:06 +0000
Re: routine for angles needed Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-05 11:37 -0700
Re: routine for angles needed Keith Thompson <kst-u@mib.org> - 2015-09-05 16:24 -0700
Re: routine for angles needed Richard Damon <Richard@Damon-Family.org> - 2015-09-05 21:01 -0400
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-09-05 23:30 -0500
Re: routine for angles needed glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-09-06 05:37 +0000
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-09-07 00:27 -0500
Re: routine for angles needed glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-09-06 05:31 +0000
Re: routine for angles needed James Kuyper <jameskuyper@verizon.net> - 2015-09-06 11:57 -0400
Re: routine for angles needed Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-09-06 17:44 +0100
Re: routine for angles needed James Kuyper <jameskuyper@verizon.net> - 2015-09-06 14:02 -0400
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-09-07 00:31 -0500
Re: routine for angles needed Keith Thompson <kst-u@mib.org> - 2015-09-06 11:59 -0700
Re: routine for angles needed Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-06 18:04 -0700
Re: routine for angles needed Keith Thompson <kst-u@mib.org> - 2015-09-06 18:30 -0700
Re: routine for angles needed Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-09-06 18:48 -0700
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-09-07 00:44 -0500
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-08-03 20:16 -0500
Re: routine for angles needed glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-04 01:26 +0000
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-08-05 02:05 -0500
Re: routine for angles needed Keith Thompson <kst-u@mib.org> - 2015-08-03 18:33 -0700
Re: routine for angles needed glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-08-04 21:24 +0000
Re: routine for angles needed Robert Wessel <robertwessel2@yahoo.com> - 2015-08-03 19:41 -0500
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 12:51 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 12:56 -0700
Re: routine for angles needed Bartc <bc@freeuk.com> - 2015-08-02 20:57 +0100
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 13:06 -0700
Re: routine for angles needed Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-08-02 22:25 +0100
Re: routine for angles needed Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-08-02 22:27 +0100
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-02 14:40 -0700
Re: routine for angles needed "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-08-02 19:08 -0700
Re: routine for angles needed fir <profesor.fir@gmail.com> - 2015-08-03 02:18 -0700
Re: routine for angles needed danncorbit@gmail.com - 2015-08-12 02:18 -0700
Re: routine for angles needed bartekltg <bartekltg@gmail.com> - 2015-09-07 05:02 +0200
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