durand-kerner

Finds all the roots of a polynomial by Weierstrass' method (or known in Abramowitz&Stegun as the Durand-Kerner method). This is basically a generalization of Newton's method that works for multiple roots.Example

To find the roots for `1 + 1*x - 1*x^2`

:
```
var findRoots = require("durand-kerner")
var roots = findRoots([1, 1, -1])
// Now:
// roots[0] = real part of roots
// roots[1] = imaginary part of roots
for(var i=0; i<roots.length; ++i) {
console.log(roots[0][i] + "+" + roots[1][i] + "i")
}
```

### Output

```
1.618033988749895+0i
-0.6180339887498949+0i
```

Install

Install using npm:`npm install durand-kerner`

API

`require("durand-kerner")(r_coeff[, i_coeff, n_iters, tolerance, initial])`

Finds the roots of a polynomial whose real coefficients are given by `r_coeff`

and imaginary coefficients by `i_coeff`

.`r_coeff`

- the real part of the polynomial's coefficients, stored in an array`i_coeff`

- the imaginary part of the polynomial's coefficients (default all 0)`n_iters`

- Maximum number of iterations to run before bailout. Default is`100 * n * n`

`tolerance`

- Stopping threshold. Default is`1e-6`

`initial`

- Initial guess for solution vector (must have the same length as`r_coeff`

). This also gets the solution (optional)

**Returns**An array of roots.

License

(c) 2013 Mikola Lysenko. MIT License