# roots: Roots of a polynomial In signal: Signal Processing

## Description

Roots of a polynomial

## Usage

 `1` ```roots(x, method = c("polyroot", "eigen")) ```

## Arguments

 `x` Polynomial coefficients with coefficients given in order from highest to lowest polynomial power. This is the Matlab/Octave convention; it is opposite of the convention used by `polyroot`. `method` Either “polyroot” (default) which uses `polyroot` for its computations internally (and is typically more accurate) or “eigen” which uses eigenvalues of the companion matrix for its computation. The latter returns complex values in case of real valued solutions in less cases.

## Value

A complex array with the roots of the polynomial.

## Author(s)

Original Octave version by Kurt Hornik. Conversion to R by Tom Short.

## References

Octave Forge https://octave.sourceforge.io/

`polyroot`, `polyval`, `poly`, `conv`
 ```1 2 3 4 5``` ```roots(1:3) polyroot(3:1) # should be the same poly(roots(1:3)) roots(1:3, method="eigen") # using eigenvalues ```