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| From: | Dmitri A. Sergatskov |
| Subject: | [Octave-bug-tracker] [bug #61143] Functions sum and mean returns wrong answer for single precision input |
| Date: | Mon, 13 Sep 2021 04:39:41 -0400 (EDT) |
| User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0 |
Follow-up Comment #21, bug #61143 (project octave):
I disagree with Kay. In Matlab's case The issue is presision;
in octave case the issue is a broken algorithm.
octave:2> (1e7 / 9999961 -1 )/ eps("single")
ans = 32.716 # error in matlab's case
octave:3> x=single(0.1*ones(1e+8,1));
octave:4> sum(x)
ans = 2097152
octave:5> (1e7 / 2097152 -1 )/ eps("single")
ans = 3.1611e+07 # error in Octave case
Dmitri.
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