ProGAL.math
Class Polynomial

java.lang.Object
  ProGAL.math.Polynomial

public class Polynomial
extends java.lang.Object

A representation of a variable sized polynomial. To find the roots of the parabola f(x) = 2x^2 + 3x - 4, for instance, write Polynomial parabola = new Polynomial(new double[]{2,3,4}); double[] roots = parabola.calcRoots(); or simply double[] roots = Polynomial.calcRoots(2,3,4); Currently this only works for polynomials of degree 2 and 3.

Author:

rfonseca

Field Summary

double[]

parameters

Method Summary

double[]	calcRoots() Find the roots of the polynomial.
static double[]	calcRoots(double[] parameters) Find the roots of the polynomial specified by the parameters.
static double[]	calcRoots(double a, double b, double c) Find the roots of a second degree polynomial.
static double[]	calcRoots(double a, double b, double c, double d) Find the roots of a third degree polynomial.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

parameters

public final double[] parameters

Method Detail

calcRoots

public double[] calcRoots()

Find the roots of the polynomial. The imaginary part is not returned.

Returns:

an array containing the roots of the polynomial

calcRoots

public static double[] calcRoots(double[] parameters)

Find the roots of the polynomial specified by the parameters. The imaginary part is not returned.

Parameters:

parameters - an array representing the coefficents of the polynomial

Returns:

an array containing the roots of the polynomial

calcRoots

public static double[] calcRoots(double a,
                                 double b,
                                 double c)

Find the roots of a second degree polynomial. The length of the returned array depends on how many roots the quadratic equation has. In other words: The imaginary part is removed completely.

Parameters:

a - coefficient of the squared term

b - coefficient of the linear term

c - coefficient of the constant

Returns:

an array containing the roots of the polynomial

calcRoots

public static double[] calcRoots(double a,
                                 double b,
                                 double c,
                                 double d)

Find the roots of a third degree polynomial. The length of the returned array depends on how many roots the cubic equation has. In other words: The imaginary part is removed completely.

Parameters:

a - coefficient of the cubed term

b - coefficient of the squared term

c - coefficient of the linear term

d - coefficient of the constant term

Returns:

an array containing the roots of the polynomial