bugGNU Octave - Bugs: bug #42238, Matrix multiplication incorrect on...

 
 

bug #42238: Matrix multiplication incorrect on large matrix

Submitted by:  None
Submitted on:  Tue 29 Apr 2014 10:24:33 PM UTC  
 
Category: Octave FunctionSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Incorrect Result
Status: Works For MeAssigned to: None
Originator Name: Kevin StoneOriginator Email: -unavailable-
Open/Closed: ClosedRelease: 3.8.1
Operating System: GNU/Linux

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Thu 25 Sep 2014 02:09:42 AM UTC, comment #3:

No further information or comments after several months, closing as working and unconfirmed.

Mike Miller <mtmiller>
Project Administrator
Wed 30 Apr 2014 01:49:12 AM UTC, comment #2:

Works for me also on Ubuntu 14.04 with 3.8.1-1ubuntu1 installed from Ubuntu repos.

Mike Miller <mtmiller>
Project Administrator
Tue 29 Apr 2014 11:20:29 PM UTC, comment #1:

Works for me using current dev 4.1.0+
And Fedora 20 on x86_64 (Intel)

octave:16> assert(ones(410241024+1,2)[1 1]',2ones(410241024+1,1));
octave:17> version
ans = 4.1.0+
octave:18>

Michael Godfrey <godfrey>
Project Member
Tue 29 Apr 2014 10:24:33 PM UTC, original submission:

Matrix multiplication is incorrect for a large matrix.

Specifically: A*B
A dim of 410241024+1 x 2
B dim of 2 x 1
assert(ones(410241024,2)[1 1]',2ones(410241024,1)); % failure

The same multiple is correct for the following dimensions:
A dim of 410241024 x 2
B dim of 2 x 1
assert(ones(410241024,2)[1 1]',2ones(410241024,1)); % success

The following is on an HP z820 running Ubuntu 14.04, Octave 3.8.1 (from default repo) with no extra octave packages installed.

Anonymous

 

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  • -unavailable- added by mtmiller (Posted a comment)
  • -unavailable- added by godfrey (Posted a comment)
  • -unavailable- added by None (Submitted the item)
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    Follow 2 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Thu 25 Sep 2014 02:09:42 AM UTCmtmillerOpen/ClosedOpen=>Closed
    Wed 30 Apr 2014 01:49:12 AM UTCmtmillerStatusNone=>Works For Me

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