[New-bugs-announce] [issue25378] Roundoff error on OS X

[Michał Jan Warecki]

New submission from Michał Jan Warecki:

This should speak for itself:

>>> 3*4.35
13.049999999999999
>>> 

The error is reproducible, and applies to all decimal numbers ending with \.[0-9]5, and \.[0-4] as well as \.[6-9], when multiplied by 3. Examples:

>>> 3*4.1
12.299999999999999
>>> 3*4.4
13.200000000000001
>>> 3*4.6
13.799999999999999
>>> 3*4.8
14.399999999999999
>>> 3*4.9
14.700000000000001
>>> 4*3.1
12.4
>>> 4*4.1
16.4
>>> 3*4.1
12.299999999999999
>>> 6*4.1
24.599999999999998
>>> 6*4.4
26.400000000000002
>>>

----------
components: Macintosh
messages: 252828
nosy: Michał Jan Warecki, ned.deily, ronaldoussoren
priority: normal
severity: normal
status: open
title: Roundoff error on OS X
type: behavior
versions: Python 2.7, Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue25378>
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