[Octave-bug-tracker] [bug #58926] Octave gives wrong results with intel-mkl when diagonalizing large matrices

[Archisman Panigrahi]

Follow-up Comment #1, bug #58926 (project octave):


[comment #0 original submission:]
> I installed octave (5.2.0) and intel-mkl (2020.0.166) from the default
repositories of Ubuntu 20.04
> 
> When I try to diagonalize a large matrix, Octave gives wrong results with
MKL (it is much faster, though).
> 
> This is the code (https://pastebin.pl/view/611d6fe3) which gives wrong
results with MKL.
> 
> ```
> for a = 1:500
>         for b = 1:500
>                 c(a,b) = sin(a + b^2);
>         endfor
> endfor
>  
> g = eig(c);
> max(real(g))
> ```
> 
> The correct result is `ans = 16.915` (I checked this before installing
intel-mkl, and also in another Ubuntu 18.04 installation in the same computer,
where intel-mkl was not installed).
> 
> With MKL in Ubuntu 20.04, I get random numbers of order 10^5 - 10^6, which
change every time the code is run.
> 
> I don't know whether this is related to
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=921207
> 
> 

    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?58926>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/