org.geotoolkit.math
Class Polynom

Object
  Polynom

All Implemented Interfaces:

Serializable

public class Polynom
extends Object
implements Serializable

The coefficients of a polynomial equation. The equation must be in the form y = c0 + c1×x + c2×x2 + c3×x3 + ... + cn×xn.

The static method roots(double[]) can be used for computing the root of a polynomial equation without creating a Polynom object.

Since:

2.0

Version:

3.00

Author:

Martin Desruisseaux (IRD), Ken Turkiwski (for algorithmic inspiration)

See Also:

Serialized Form

Module:

utility/geotk-utility (download)

View source code for this class

Constructor Summary

Polynom(double[] c)
Constructs a polynomial equation with the specified coefficients.

Method Summary

boolean	equals(Object object) Compares this polynom with the specified object for equality.
int	hashCode() Returns a hash value for this polynom.
double[]	roots() Finds the roots of the polynomial equation.
static double[]	roots(double[] c) Finds the roots of a polynomial equation.
String	toString() Returns a string representation of this polynom.
double	y(double x) Evaluates the polynomial equation for the specified x value.

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Polynom

public Polynom(double[] c)

Constructs a polynomial equation with the specified coefficients.

Parameters:

c - The coefficients. This array is copied.

Method Detail

y

public final double y(double x)

Evaluates the polynomial equation for the specified x value. More specifically, this method computes c0 + c1×x + c2×x2 + c3×x3 + ... + cn×xn.

Parameters:

x - The value where to evaluate the polynomial equation.

Returns:

The result of the evaluation at the given value.

roots

public double[] roots()

Finds the roots of the polynomial equation.

Returns:

The roots.

roots

public static double[] roots(double[] c)

Finds the roots of a polynomial equation. More specifically, this method solve the following equation:

c[0] + c[1]*x + c[2]*x2 + c[3]*x3 + ... + c[n]*xn == 0

where n is the array length minus 1.

Parameters:

c - The coefficients for the polynomial equation.

Returns:

The roots. This array may have any length up to n-1.

Throws:

UnsupportedOperationException - if there is more coefficients than this method can handle.

hashCode

public int hashCode()

Returns a hash value for this polynom.

Overrides:

hashCode in class Object

equals

public boolean equals(Object object)

Compares this polynom with the specified object for equality.

Overrides:

equals in class Object

Parameters:

object - The object to compare with this polynom.

Returns:

true if both objects are equal.

toString

public String toString()

Returns a string representation of this polynom.

Overrides:

toString in class Object