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Groups > comp.lang.python > #77986
| From | Terry Reedy <tjreedy@udel.edu> |
|---|---|
| Subject | Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` |
| Date | 2014-09-17 19:23 -0400 |
| References | <06397cb3-8baf-4af1-8152-ff7c3f6ceb62@googlegroups.com> <mailman.14066.1410916403.18130.python-list@python.org> <fd859066-7068-4a43-a9f0-0e9cc6949cf6@googlegroups.com> |
| Newsgroups | comp.lang.python |
| Message-ID | <mailman.14091.1410996269.18130.python-list@python.org> (permalink) |
On 9/17/2014 10:55 AM, cool-RR wrote:
> Terry, that doesn't really answer the question "why", it just pushes
> it back to the documentation. Is there a real answer why? Why return
> NaN when Inf would make mathematical sense?
IEEE float('inf') and float('nan') are engineering, not math constructs.
I showed that the result is consistent with the math definition.
Another result (including raising) might be also. Many choices
concerting inf and nan are arbitrary and any 'why' can be debated.
--
Terry Jan Reedy
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Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` cool-RR <ram.rachum@gmail.com> - 2014-09-16 14:40 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Terry Reedy <tjreedy@udel.edu> - 2014-09-16 21:12 -0400
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` cool-RR <ram.rachum@gmail.com> - 2014-09-17 07:55 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Chris Angelico <rosuav@gmail.com> - 2014-09-18 01:10 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` cool-RR <ram.rachum@gmail.com> - 2014-09-17 08:16 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Chris Angelico <rosuav@gmail.com> - 2014-09-18 01:29 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` cool-RR <ram.rachum@gmail.com> - 2014-09-17 09:33 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Chris Angelico <rosuav@gmail.com> - 2014-09-18 02:37 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-09-18 13:11 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` cool-RR <ram.rachum@gmail.com> - 2014-09-18 01:43 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Ian Kelly <ian.g.kelly@gmail.com> - 2014-09-17 09:34 -0600
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Chris Angelico <rosuav@gmail.com> - 2014-09-18 01:40 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-09-18 12:50 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Ian Kelly <ian.g.kelly@gmail.com> - 2014-09-17 10:12 -0600
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Ian Kelly <ian.g.kelly@gmail.com> - 2014-09-17 10:30 -0600
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Ian Kelly <ian.g.kelly@gmail.com> - 2014-09-17 12:03 -0600
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Chris Angelico <rosuav@gmail.com> - 2014-09-18 07:37 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-09-18 13:29 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Chris Angelico <rosuav@gmail.com> - 2014-09-18 13:47 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Terry Reedy <tjreedy@udel.edu> - 2014-09-17 19:23 -0400
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Ian Kelly <ian.g.kelly@gmail.com> - 2014-09-18 00:51 -0600
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Ian Kelly <ian.g.kelly@gmail.com> - 2014-09-17 09:35 -0600
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` wxjmfauth@gmail.com - 2014-09-17 23:22 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Marko Rauhamaa <marko@pacujo.net> - 2014-09-18 09:45 +0300
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` wxjmfauth@gmail.com - 2014-09-18 00:13 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-09-18 19:25 +1000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` wxjmfauth@gmail.com - 2014-09-18 05:57 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Grant Edwards <invalid@invalid.invalid> - 2014-09-18 14:33 +0000
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` chris.barker@noaa.gov - 2014-09-18 09:35 -0700
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` Ian Kelly <ian.g.kelly@gmail.com> - 2014-09-18 11:05 -0600
Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` wxjmfauth@gmail.com - 2014-09-18 23:48 -0700
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