umontreal.iro.lecuyer.functionfit
Class PolInterp

java.lang.Object
  umontreal.iro.lecuyer.functions.Polynomial
      umontreal.iro.lecuyer.functionfit.PolInterp

All Implemented Interfaces:

Serializable, Cloneable, MathFunction, MathFunctionWithDerivative, MathFunctionWithFirstDerivative, MathFunctionWithIntegral

public class PolInterp
extends Polynomial
implements Serializable

Represents a polynomial that interpolates through a set of points. More specifically, let (x₀, y₀),…,(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.

See Also:

Serialized Form

Constructor Summary

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

Method Summary

PolInterp	clone()
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]).
double[]	getX() Returns the x coordinates of the interpolated points.
double[]	getY() Returns the y coordinates of the interpolated points.
String	toString()
static String	toString(double[] x, double[] y) Makes a string representation of a set of points.

Methods inherited from class umontreal.iro.lecuyer.functions.Polynomial

derivative, derivative, derivativePolynomial, evaluate, getCoefficient, getCoefficients, getDegree, integral, integralPolynomial, setCoefficients

Methods inherited from class java.lang.Object

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

Constructor Detail

PolInterp

public 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.

Throws:

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.

Method Detail

getCoefficients

public 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]). 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.

getX

public double[] getX()

Returns the x coordinates of the interpolated points.

Returns:

the x coordinates of the interpolated points.

getY

public double[] getY()

Returns the y coordinates of the interpolated points.

Returns:

the y coordinates of the interpolated points.

toString

public static String toString(double[] x,
                              double[] y)

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.

toString

public String toString()

Overrides:

toString in class Polynomial

clone

public PolInterp clone()

Overrides:

clone in class Polynomial