umontreal.ssj.functionfit.PolInterp Class Reference

Represents a polynomial that interpolates through a set of points. More...

Inheritance diagram for umontreal.ssj.functionfit.PolInterp:

Public Member Functions
	PolInterp (double[] x, double[] y)
	Constructs a new polynomial interpolating through the given points (x[0], y[0]), ..., (x[n], y[n]).
double[]	getX ()
	Returns the \(x\) coordinates of the interpolated points.
double[]	getY ()
	Returns the \(y\) coordinates of the interpolated points.
String	toString ()
	Calls toString(double[], double[]) with the associated points.
Public Member Functions inherited from umontreal.ssj.functions.Polynomial
	Polynomial (double... coeff)
	Constructs a new polynomial with coefficients coeff.
int	getDegree ()
	Returns the degree of this polynomial.
double[]	getCoefficients ()
	Returns an array containing the coefficients of the polynomial.
double	getCoefficient (int i)
	Returns the \(i\)th coefficient of the polynomial.
void	setCoefficients (double... coeff)
	Sets the array of coefficients of this polynomial to coeff.
double	evaluate (double x)
	Returns the value of the function evaluated at \(x\).
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 \(n\)th derivative of the function at point x.
Polynomial	derivativePolynomial (int n)
	Returns a polynomial corresponding to the \(n\)th derivative 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.

Static Public Member Functions
static double[]	getCoefficients (double[] x, double[] y)
	Computes and returns the coefficients the polynomial interpolating through the given points (x[0], y[0]), ..., (x[n], y[n]).
static String	toString (double[] x, double[] y)
	Makes a string representation of a set of points.

Detailed Description

Represents a polynomial that interpolates through a set of points.

More specifically, let \((x_0,y_0), …, (x_n, y_n)\) be a set of points and

\(p(x)\) the constructed polynomial of degree \(n\). Then, for \(i=0,…,n\), \(p(x_i)=y_i\).

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Definition at line 44 of file PolInterp.java.

Constructor & Destructor Documentation

PolInterp()

umontreal.ssj.functionfit.PolInterp.PolInterp	(	double[]	x,
		double[]	y )

Constructs a new polynomial interpolating through the given points (x[0], y[0]), ..., (x[n], y[n]).

This constructs a polynomial of degree n from n+1 points.

Parameters

x	the \(x\) coordinates of the points.
y	the \(y\) coordinates of the points.

Exceptions

NullPointerException	if `x` or `y` are `null`.
IllegalArgumentException	if the lengths of `x` and `y` are different, or if less than two points are specified.

Definition at line 62 of file PolInterp.java.

Member Function Documentation

getCoefficients()

double[] umontreal.ssj.functionfit.PolInterp.getCoefficients ( double[] x, double[] y )

static

Computes and returns the coefficients the polynomial interpolating through the given points (x[0], y[0]), ..., (x[n], y[n]).

This polynomial has degree n and there are n+1 coefficients.

Parameters

x	the \(x\) coordinates of the points.
y	the \(y\) coordinates of the points.

Returns

the coefficients the interpolating polynomial.

Definition at line 77 of file PolInterp.java.

getX()

double[] umontreal.ssj.functionfit.PolInterp.getX

(

)

Returns the \(x\) coordinates of the interpolated points.

Returns

the \(x\) coordinates of the interpolated points.

Definition at line 101 of file PolInterp.java.

getY()

double[] umontreal.ssj.functionfit.PolInterp.getY

(

)

Returns the \(y\) coordinates of the interpolated points.

Returns

the \(y\) coordinates of the interpolated points.

Definition at line 110 of file PolInterp.java.

toString() [1/2]

String umontreal.ssj.functionfit.PolInterp.toString

(

)

Calls toString(double[], double[]) with the associated points.

Returns

a string containing the points.

Reimplemented from umontreal.ssj.functions.Polynomial.

Definition at line 140 of file PolInterp.java.

toString() [2/2]

String umontreal.ssj.functionfit.PolInterp.toString ( double[] x, double[] y )

static

Makes a string representation of a set of points.

Parameters

x	the \(x\) coordinates of the points.
y	the \(y\) coordinates of the points.

Returns

the string representing the points.

Definition at line 121 of file PolInterp.java.

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The documentation for this class was generated from the following file:

• src/main/java/umontreal/ssj/functionfit/PolInterp.java