Hi everyone!
I need to find the roots of some quite big polynomials (order ~800).
The
root function works fine (and surprisingly fast!), but I don't think
it's the best tool forwhat I need. I'm only interested in those roots
with high absolute value, so after "roots" works hard to find the 800
complex values, I discard almost all of them.
Do you have any suggestion for an algorithm to do that?
I did find a book on the subject (McNamee - Numerical Methods for
Roots
of Polynomials, Vol1 - 2007), and it suggest (I didn't read it
thoroughly, yet) that the companion method finds the roots one by one,
starting with the one with the largest magnitude. However, there are a
multitude of similar methods in the book.
Is Octave doing that?