[Numpy-discussion] roots and high-order polynomial

[Charles R Harris]

On Fri, Jul 3, 2009 at 3:48 AM, Fabrice Silva <silva at lma.cnrs-mrs.fr> wrote:

> Hello
> Has anyone looked at the behaviour of the (polynomial) roots function
> for high-order polynomials ? I have an application which internally
> searches for the roots of a polynomial. It works nicely for order less
> than 20, and then has an erratic behaviour for upper values...
>

What do you mean by erratic? Are the computed roots different from known
roots? The connection between polynomial coefficients and polynomial values
becomes somewhat vague when the polynomial degree becomes large, it is
numerically ill conditioned.

Chuck
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