num-roots
▸ function numRoots
(p: number[]): number
Defined in roots/descartes/double/num-roots.ts:35
Returns the exact number of distinct real roots in the interval (-∞,+∞) of the given polynomial - subject to floating point underflow / overflow of intermediate calculations.
- From Wikipedia: "In the case of a non-square-free polynomial, if neither a nor b is a multiple root of p, then V(a) − V(b) is the number of distinct real roots of P".
example
const p = [1, 1, -64, 236, -240];
numRoots(p); //=> 4
Parameters:
| Name | Type | Description |
|---|---|---|
p | number[] | a polynomial with coefficients given densely as an array of double floating point numbers from highest to lowest power, e.g. [5,-3,0] represents the polynomial 5x^2 - 3x |
Returns: number