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[Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result
From: |
Rik |
Subject: |
[Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result |
Date: |
Wed, 9 May 2018 15:10:19 -0400 (EDT) |
User-agent: |
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:55.0) Gecko/20100101 Firefox/55.0 |
Update of bug #53869 (project octave):
Status: Need Info => Confirmed
_______________________________________________________
Follow-up Comment #4:
Confirmed. Calling residue_bug with n = 1,2 works fine. However, with n = 3
there is already a warning printed and the condition number of the matrix is
scarily high.
octave:6> debug_on_warning (1)
octave:7> residue_bug (3)
warning: matrix singular to machine precision, rcond = 5.73398e-20
warning: called from
residue at line 265 column 5
residue_bug at line 6 column 11
stopped in /home/rik/wip/Projects_Mine/octave-dev/scripts/polynomial/residue.m
at line 265
265: r = A \ B;
The residue algorithm is coded as an m-file so it should be easy to see why A
is nearly singlular. However, I don't understand the algorithm well enough to
say how it should be modified or replaced.
_______________________________________________________
Reply to this item at:
<http://savannah.gnu.org/bugs/?53869>
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- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, anonymous, 2018/05/09
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, Rik, 2018/05/09
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, Tony Richardson, 2018/05/09
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, Tony Richardson, 2018/05/09
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result,
Rik <=
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, Tony Richardson, 2018/05/10
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, Marco Caliari, 2018/05/12
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, Rik, 2018/05/14
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, Marco Caliari, 2018/05/15
- [Octave-bug-tracker] [bug #53869] Residue returning an inaccurate result, Rik, 2018/05/15