[Octave-bug-tracker] [bug #38628] bsxfun slow for complex

[Vincent Gras]

Follow-up Comment #10, bug #38628 (project octave):

Hi, here is a piece of code that I found to be very slow in octave:

G = bsxfun(@times, eye(Nc, Nc), shiftdim(F, -2));

(dimensions for F (complex array) were 7x11189 and Nc was equal to 8,
computation time was 8.96s)

Then I found this discussion. I effectively managed to recover a normal
execution time using the following trick:


Gr = bsxfun(@times, eye(Nc, Nc), shiftdim(real(F), -2));
Gi = bsxfun(@times, eye(Nc, Nc), shiftdim(imag(F), -2));
G = complex(Gr, Gi);

(computation time down to 0.75s !)

That would be great however if the issue could be fixed in a later revision of
octave.






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