SSJ
V. 2.6.

## umontreal.iro.lecuyer.functions Class Polynomial

java.lang.Object
umontreal.iro.lecuyer.functions.Polynomial
All Implemented Interfaces:
Serializable, Cloneable, MathFunction, MathFunctionWithDerivative, MathFunctionWithFirstDerivative, MathFunctionWithIntegral
Direct Known Subclasses:
PolInterp

public class Polynomial
extends Object
implements MathFunction, MathFunctionWithFirstDerivative, MathFunctionWithDerivative, MathFunctionWithIntegral, Serializable, Cloneable

Represents a polynomial of degree n in power form. Such a polynomial is of the form

p(x) = c0 + c1x + ... + cnxn,

where c0,…, cn are the coefficients of the polynomial.

Serialized Form

Constructor Summary
Polynomial(double... coeff)
Constructs a new polynomial with coefficients coeff.

Method Summary
Polynomial clone()

double derivative(double x)
Computes (or estimates) the first derivative of the function at point x.
double derivative(double x, int n)
Computes (or estimates) the nth derivative of the function at point x.
Polynomial derivativePolynomial(int n)
Returns a polynomial corresponding to the nth derivative of this polynomial.
double evaluate(double x)
Returns the value of the function evaluated at x.
double getCoefficient(int i)
Returns the ith coefficient of the polynomial.
double[] getCoefficients()
Returns an array containing the coefficients of the polynomial.
int getDegree()
Returns the degree of this polynomial.
double integral(double a, double b)
Computes (or estimates) the integral of the function over the interval [a, b].
Polynomial integralPolynomial(double c)
Returns a polynomial representing the integral of this polynomial.
void setCoefficients(double... coeff)
Sets the array of coefficients of this polynomial to coeff.
String toString()

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

### Polynomial

public Polynomial(double... coeff)
Constructs a new polynomial with coefficients coeff. The value of coeff[i] in this array corresponds to ci.

Parameters:
coeff - the coefficients of the polynomial.
Throws:
NullPointerException - if coeff is null.
IllegalArgumentException - if the length of coeff is 0.
Method Detail

### getDegree

public int getDegree()
Returns the degree of this polynomial.

Returns:
the degree of this polynomial.

### getCoefficients

public double[] getCoefficients()
Returns an array containing the coefficients of the polynomial.

Returns:
the array of coefficients.

### getCoefficient

public double getCoefficient(int i)
Returns the ith coefficient of the polynomial.

Returns:
the array of coefficients.

### setCoefficients

public void setCoefficients(double... coeff)
Sets the array of coefficients of this polynomial to coeff.

Parameters:
coeff - the new array of coefficients.
Throws:
NullPointerException - if coeff is null.
IllegalArgumentException - if the length of coeff is 0.

### evaluate

public double evaluate(double x)
Description copied from interface: MathFunction
Returns the value of the function evaluated at x.

Specified by:
evaluate in interface MathFunction
Parameters:
x - value at which the function is evaluated
Returns:
function evaluated at x

### derivative

public double derivative(double x)
Description copied from interface: MathFunctionWithFirstDerivative
Computes (or estimates) the first derivative of the function at point x.

Specified by:
derivative in interface MathFunctionWithFirstDerivative
Parameters:
x - the point to evaluate the derivative to.
Returns:
the value of the derivative.

### derivative

public double derivative(double x,
int n)
Description copied from interface: MathFunctionWithDerivative
Computes (or estimates) the nth derivative of the function at point x. For n = 0, this returns the result of evaluate.

Specified by:
derivative in interface MathFunctionWithDerivative
Parameters:
x - the point to evaluate the derivate to.
n - the order of the derivative.
Returns:
the resulting derivative.

### derivativePolynomial

public Polynomial derivativePolynomial(int n)
Returns a polynomial corresponding to the nth derivative of this polynomial.

Parameters:
n - the degree of the derivative.
Returns:
the derivative.

### integral

public double integral(double a,
double b)
Description copied from interface: MathFunctionWithIntegral
Computes (or estimates) the integral of the function over the interval [a, b].

Specified by:
integral in interface MathFunctionWithIntegral
Parameters:
a - the starting point of the interval.
b - the ending point of the interval.
Returns:
the value of the integral.

### integralPolynomial

public Polynomial integralPolynomial(double c)
Returns a polynomial representing the integral of this polynomial. This integral is of the form

p(x)dx = c + c0x + 1#1 + ... + 2#2,

where c is a user-defined constant.

Parameters:
c - the constant for the integral.
Returns:
the polynomial representing the integral.

### toString

public String toString()
Overrides:
toString in class Object

### clone

public Polynomial clone()
Overrides:
clone in class Object

SSJ
V. 2.6.

To submit a bug or ask questions, send an e-mail to Pierre L'Ecuyer.