org.opensourcephysics.numerics
Class Polynomial

java.lang.Object
  org.opensourcephysics.numerics.Polynomial

All Implemented Interfaces:

Function

Direct Known Subclasses:

PolynomialLeastSquareFit

public class Polynomial
extends java.lang.Object
implements Function

Polynomial implements a mathematical polynomial: c[0] + c[1] * x + c[2] * x^2 + .... This class is based on code published in Object-Oriented Implementation of Numerical Methods by Didier H. Besset. The code has been adapted to the OSP framework by Wolfgang Christian.

Field Summary

protected double[]

coefficients Polynomial coefficients.

Constructor Summary

Polynomial(double[] coef)
Constructs a polynomial with the given coefficients.

Polynomial(java.lang.String[] coef)
Constructs a polynomial with the given coefficients.

Method Summary

Polynomial	add(double r)
Polynomial	add(Polynomial p) Adds the given polynomial to this polynomial.
double	coefficient(int n) Gets the coefficient value at the desired position
Polynomial	deflate(double r) Deflates the polynomial by removing the root.
int	degree() Gets the degree of this polynomial function.
Polynomial	derivative() Gets the derivative of this polynomial.
Polynomial	divide(double r) Divides this polynomial by a constant.
Polynomial	divide(Polynomial p) Divides this polynomial by another polynomial.
Polynomial[]	divideWithRemainder(Polynomial p) Divides this polynomial by another polynomial.
static double	evalPolynomial(double x, double[] coeff) Evaluates a polynomial using the given coefficients.
double	evaluate(double x) Evaluates the polynomial for the specified variable value.
double[]	getCoefficients() Gets a clone of the polynomial coefficients c: c[0] + c[1] * x + c[2] * x^2 + ....
Polynomial	integral() Integrates this polynomial.
Polynomial	integral(double value) Integrates this polynomial having the specified value for x = 0.
Polynomial	multiply(double r) Multiplies this polynomial by a constant.
Polynomial	multiply(Polynomial p) Multiplies this polynomial by another polynomial.
double[][]	roots() Gets the complex roots of this polynomial.
double[]	rootsReal() Gets the real roots of this polynomial.
Polynomial	subtract(double r) Subtracts a constant from this polynomial.
Polynomial	subtract(Polynomial p) Subtracts another polynomial from this polynomial.
java.lang.String	toString() Converts this polynomial to a String.
double[]	valueAndDerivative(double x) Returns the value and the derivative of this polynomial for the specified variable value in an array of two elements

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

coefficients

protected double[] coefficients

Polynomial coefficients.

Constructor Detail

Polynomial

public Polynomial(double[] coef)

Constructs a polynomial with the given coefficients.

Parameters:

coef - polynomial coefficients.

Polynomial

public Polynomial(java.lang.String[] coef)

Constructs a polynomial with the given coefficients.

Parameters:

coef - polynomial coefficients.

Method Detail

getCoefficients

public double[] getCoefficients()

Gets a clone of the polynomial coefficients c: c[0] + c[1] * x + c[2] * x^2 + ....

Returns:

double[]

evalPolynomial

public static double evalPolynomial(double x,
                                    double[] coeff)

Evaluates a polynomial using the given coefficients.

Parameters:

x -

coeff - the polynomial coefficients.

add

public Polynomial add(double r)

Parameters:

r - double number added to the polynomial.

Returns:

Polynomial

add

public Polynomial add(Polynomial p)

Adds the given polynomial to this polynomial.

Parameters:

p - Polynomial

Returns:

Polynomial

coefficient

public double coefficient(int n)

Gets the coefficient value at the desired position

Parameters:

n - int the position of the coefficient to be returned

Returns:

double the coefficient value

deflate

public Polynomial deflate(double r)

Deflates the polynomial by removing the root.

Parameters:

r - double a root of the polynomial (no check made).

Returns:

Polynomial the receiver divided by polynomial (x - r).

degree

public int degree()

Gets the degree of this polynomial function.

Returns:

int degree of this polynomial function

derivative

public Polynomial derivative()

Gets the derivative of this polynomial.

Returns:

Polynomial the derivative.

divide

public Polynomial divide(double r)

Divides this polynomial by a constant.

Parameters:

r - double

Returns:

Polynomial

divide

public Polynomial divide(Polynomial p)

Divides this polynomial by another polynomial. The remainder is dropped.

Parameters:

p - Polynomial

Returns:

Polynomial

divideWithRemainder

public Polynomial[] divideWithRemainder(Polynomial p)

Divides this polynomial by another polynomial.

Parameters:

p - polynomial

Returns:

polynomial array containing the answer and remainder

integral

public Polynomial integral()

Integrates this polynomial. The integral has the value 0 at x = 0.

Returns:

Polynomial the integral

integral

public Polynomial integral(double value)

Integrates this polynomial having the specified value for x = 0.

Parameters:

value - double value of the integral at x=0

Returns:

Polynomial the integral.

multiply

public Polynomial multiply(double r)

Multiplies this polynomial by a constant.

Parameters:

r - double

Returns:

Polynomial

multiply

public Polynomial multiply(Polynomial p)

Multiplies this polynomial by another polynomial.

Parameters:

p - Polynomial

Returns:

Polynomial

roots

public double[][] roots()

Gets the complex roots of this polynomial.

Returns:

double[]

rootsReal

public double[] rootsReal()

Gets the real roots of this polynomial.

Returns:

double[]

subtract

public Polynomial subtract(double r)

Subtracts a constant from this polynomial.

Parameters:

r - the constant

Returns:

Polynomial

subtract

public Polynomial subtract(Polynomial p)

Subtracts another polynomial from this polynomial.

Parameters:

p - Polynomial

Returns:

Polynomial

toString

public java.lang.String toString()

Converts this polynomial to a String.

Overrides:

toString in class java.lang.Object

evaluate

public double evaluate(double x)

Evaluates the polynomial for the specified variable value.

Specified by:

evaluate in interface Function

Parameters:

x - double value at which the polynomial is evaluated

Returns:

double polynomial value.

valueAndDerivative

public double[] valueAndDerivative(double x)

Returns the value and the derivative of this polynomial for the specified variable value in an array of two elements

Parameters:

x - double value at which the polynomial is evaluated

Returns:

double[0] the value of the polynomial