[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
Roundup Robot devn...@psf.upfronthosting.co.za added the comment: New changeset de1ecda2afa2 by Mark Dickinson in branch '2.7': Issue #12245: Document sys.float_info.rounds better. http://hg.python.org/cpython/rev/de1ecda2afa2 New changeset 795c184b0282 by Mark Dickinson in branch '3.2': Issue #12245: Document sys.float_info.rounds better. http://hg.python.org/cpython/rev/795c184b0282 New changeset 5e45dfc421e4 by Mark Dickinson in branch 'default': Issue #12245 merge. http://hg.python.org/cpython/rev/5e45dfc421e4 -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
Changes by Mark Dickinson dicki...@gmail.com: -- resolution: - fixed status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
Ezio Melotti ezio.melo...@gmail.com added the comment: LGTM -- nosy: +ezio.melotti stage: - commit review ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
Mark Dickinson dicki...@gmail.com added the comment: all it does is give information about the FPU settings at the time that Python was compiled Hmm. It's actually a bit better than that: as far as I can tell, it reflects the value of FLT_ROUNDS at the time that Python is started (when the sys module is initialized). OTOH, FLT_ROUNDS on my machine is #define'd to be 1, in violation of the C standards. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
Mark Dickinson dicki...@gmail.com added the comment: Patch that elaborates a bit on the meaning of sys.float_info.rounds. -- keywords: +patch Added file: http://bugs.python.org/file22454/issue12245.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
Mark Dickinson dicki...@gmail.com added the comment: float_info.rounds is a bit of an odd fish, and I think it was probably a mistake to include it in sys.float_info in the first place. All the other float_info fields relate to parameters of the floating-point format, which is fixed, useful information. In contrast, float_info.rounds gives information about the current FPU settings, which are variable. Moreover, it doesn't do that very well: all it does is give information about the FPU settings at the time that Python was compiled, which isn't really very helpful (and perhaps not even that: it reports the value of FLT_ROUNDS, which may not even reflect those FPU settings accurately). I wouldn't mind seeing this field fade quietly into obscurity. FWIW, the value is taken from C's FLT_ROUNDS, and its interpretation is *supposed* to be the following (C99 5.2.4.2.2, para 7): -1: The compiler was unable to determine rounding mode. 0: Round towards zero. 1: Round to nearest (this is the most likely value for float_info.rounds on common platforms). 2: Round towards positive infinity 3: Round towards negative infinity. -- nosy: +mark.dickinson ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
Changes by Mark Dickinson dicki...@gmail.com: -- nosy: +christian.heimes ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
Changes by Mark Dickinson dicki...@gmail.com: -- assignee: docs@python - mark.dickinson ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12245] Document the meaning of FLT_ROUNDS constants for sys.float_info
New submission from Raymond Hettinger raymond.hettin...@gmail.com: sys.float_info.rounds 1 -- assignee: docs@python components: Documentation messages: 137493 nosy: docs@python, rhettinger priority: normal severity: normal status: open title: Document the meaning of FLT_ROUNDS constants for sys.float_info versions: Python 2.7, Python 3.2, Python 3.3 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12245 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
