bugGNU Octave - Bugs: bug #43871, fzero produces innacurate results...

 
 

bug #43871: fzero produces innacurate results (while MATLAB produces analytically correct one +-eps)

Submitted by:  Fedja Beader <specing>
Submitted on:  Mon 22 Dec 2014 06:14:44 PM UTC  
 
Category: Octave FunctionSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Inaccurate Result
Status: DuplicateAssigned to: None
Originator Name: Open/Closed: Closed
Release: 3.8.2Operating System: Any

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Mon 22 Dec 2014 09:05:44 PM UTC, comment #1:

The tolerance for X has been changed from 1e-8 to eps in this changeset: http://hg.savannah.gnu.org/hgweb/octave/rev/6e0686858b6a
,see also bug #41000.

You can fix your local fzero.m until the changeset makes it into a stable release or use "TolX".

Andreas Weber <andy1978>
Project Member
Mon 22 Dec 2014 06:14:44 PM UTC, original submission:

function v = legendre(n, x)

if (n == 0)
v = 1;
elseif (n == 1)
v = x;
else
v = (2 .* n - 1) .* x .* legendre(n - 1, x) - (n - 1) .* legendre(n - 2, x);
v = v ./ n;
end
end

Fedja Beader <specing>

 

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  • -unavailable- added by andy1978 (Posted a comment)
  • -unavailable- added by specing (Submitted the item)
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    Follow 3 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Mon 22 Dec 2014 09:08:10 PM UTCandy1978StatusNone=>Duplicate
      Open/ClosedOpen=>Closed
    Mon 22 Dec 2014 09:05:44 PM UTCandy1978Dependencies-=>Depends on bugs #41000

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