R: Define Polynomial by Roots

Poly {pracma} | R Documentation

## Define Polynomial by Roots

### Description

Define a polynomial by its roots.

### Usage

      Poly(x)

### Arguments

`x` | vector or square matrix

### Details

Computes the characteristic polynomial of an (n x n)-Matrix.

If `x` is a vector, `Poly(x)` is the vector of coefficients of the polynomial whose roots are the elements of `x`.

### Value

Vector representing a polynomial.

### Note

In Matlab/Octave this function is called `poly()`.

### See Also

`polyval`, `roots`

### Examples

      Poly(c(1, -1, 1i, -1i))  # Solves x^4 -1 = 0
      # Wilkinson's example:
      roots(Poly(1:20))

[Package pracma version 2.0.4 Index]