[Octave-bug-tracker] [bug #44849] expm() produces incorrect result

[Philip Nienhuis]

Update of bug #44849 (project octave):

                  Status:                    None => Need Info              

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Follow-up Comment #2:

I'm afraid you made a typo.
On the page you mentioned, matrix A is defined as:

A = [0,-0.785398,0;0.785398,0,0;0,0,0];

rather than 

A = [0,-0.785398,0;0.785398,0,0;0,0,1];  ## See last element!

With the proper A, both Octave-3.8.2 and Octave-4.0.0-rc4 do:

>> A = [0,-0.785398,0;0.785398,0,0;0,0,0];
>> expm(A)
ans =

   0.70711  -0.70711   0.00000
   0.70711   0.70711   0.00000
   0.00000   0.00000   1.00000


With that out of the way, how about the n=47 and n=111 sized matrices? Do you
have examples with expected outcomes?

BTW Octave-3.6.4 is quite old. Better upgrade to 3.8.2 at least, or wait a
month or so and you'll have 4.0.0.

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