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[Octave-bug-tracker] [bug #42589] Inaccurate results with the colon oper
From: |
Michael Godfrey |
Subject: |
[Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator |
Date: |
Sun, 22 Jun 2014 20:58:06 +0000 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:30.0) Gecko/20100101 Firefox/30.0 |
Follow-up Comment #24, bug #42589 (project octave):
@Rik,
I was afraid of that. This is the same argument that Matlab
has used. They even go so far as to not allow Matlab to
run on systems which do not provide bit-compatibility. There
was a time when this excluded a significant number of
machines. But, in any case, it reduced their numerical
accuracy.
Note that leaving extended bits on does not mean
that they need to be preserved. As Kahan points out
and his example shows, precision is improved with the
bits ignored. I have not reviewed all the current processor's
FP 754 adherence, but I suspect that practically all
current processors would yield the same results with
extended bits on, but ignored.
You might want to look at:
http://www.cs.berkeley.edu/~wkahan/Mindless.pdf
When this is decided, it would be good to document it.
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- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, (continued)
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Julien Bect, 2014/06/21
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Julien Bect, 2014/06/21
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Michael Godfrey, 2014/06/21
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Rik, 2014/06/21
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Michael Godfrey, 2014/06/21
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Julien Bect, 2014/06/21
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Rik, 2014/06/21
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Julien Bect, 2014/06/22
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Michael Godfrey, 2014/06/22
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Rik, 2014/06/22
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator,
Michael Godfrey <=
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Jordi GutiƩrrez Hermoso, 2014/06/23
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Julien Bect, 2014/06/24
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Julien Bect, 2014/06/24
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Rik, 2014/06/24
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Michael Godfrey, 2014/06/24
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, John W. Eaton, 2014/06/24
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Rik, 2014/06/24
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, John W. Eaton, 2014/06/24
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Rik, 2014/06/24
- [Octave-bug-tracker] [bug #42589] Inaccurate results with the colon operator, Rik, 2014/06/26