bugGNU Octave - Bugs: bug #43717, rats LEN Matlab incompatibility


bug #43717: rats LEN Matlab incompatibility

Submitted by:  Andreas Weber <andy1978>
Submitted on:  Thu 27 Nov 2014 08:27:40 PM UTC  
Category: Octave FunctionSeverity: 3 - Normal
Priority: 3 - LowItem Group: WTF, Matlab?!?
Status: NoneAssigned to: None
Originator Name: Open/Closed: Open
Release: 3.8.2Operating System: Any

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Thu 27 Nov 2014 08:27:40 PM UTC, original submission:

Octave tries to find an approximation which fits into LEN (second arg of rats) but Matlab seems to do some fancy stuff to calculate a tolerance from the input vector X and LEN and then call rat with this tolerance. The strings returned from Matlab are often less shorter than LEN even if a better approximation would be possible.

For example octave returns 22/7 for rats(pi, 4) whereas Matlab returns " *", see http://octave.1599824.n4.nabble.com/Matlab-output-from-quot-rats-quot-wanted-tt4667406.html and the Matlab documentation under More About - Algorithms.

Personally I think Octave's behaviour is much better here but I want to document this here.

If someone want to investigate this further: Try a changeset after c490eac28bbb which fixed an overflow in rats (#43369).

Andreas Weber <andy1978>
Project Member


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    Follow 2 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Thu 01 Jan 2015 02:58:27 PM UTCandy1978Item GroupMatlab Compatibility=>WTF, Matlab?!?
    Wed 31 Dec 2014 06:35:48 PM UTCrik5Priority5 - Normal=>3 - Low

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