[Octave-bug-tracker] [bug #61129] Improve performance of factor() function

[Michael Leitner]

Follow-up Comment #18, bug #61129 (project octave):

Just out of interest: does anybody have an idea why there is this speed-up of
a factor 4 even for large prime inputs q? As I see it, in this case both the
old and the new code compute the list of primes up to sqrt(q) and then test
which of those divides q (in a vectorized statement). None does, so it returns
with the answer that q is prime. And here the call to primes() should take
most of the effort, but this code was not altered.

In any case, a minimum increase of a factor 4 for all large inputs is also
very noteworthy.

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