horner

horner

Evaluates polynomials using Horner's rule.

Use

First install via npm:

npm install horner

Then you can use it as follows:

var horner = require("horner")


//Example:  Evaluate the polynomial 1 + 2 * x^2 at x = 2
console.log(horner([1, 0, 2], 2.0))

//Prints:  9

//Example:  Evaluate a complex polynomial
//
//      2 - 3i * x + (4 + 5i)*x^2
//
// At x = 1+2i

console.log(horner([[2, 0, 4]     //Real coefficients
                  , [0, -3, 5]]   //Imaginary coefficients
                  , [1, 2]))

//Prints: [-24,-2]

require("horner")(poly, z)

Evaluates the polynomial at the point z

• poly is the coefficients of the polynomial arranged in increasing degree. If complex, is a pair of arrays, the first representing the real coefficients and the second representing the imaginary coefficients.
• z is the point to evaluate the polynomial at. Either a scalar for a real valued function or a pair for a complex number.

Returns: A scalar for real results, a pair for complex results

Time Complexity: O(poly.length)

Credits

(c) 2013 Mikola Lysenko. MIT License