org.apache.commons.math.analysis.interpolation
Class BicubicSplineFunction

java.lang.Object
  org.apache.commons.math.analysis.interpolation.BicubicSplineFunction

All Implemented Interfaces:

BivariateRealFunction

 class BicubicSplineFunction
extends java.lang.Object
implements BivariateRealFunction

2D-spline function.

Version:

$Revision$ $Date$

Field Summary

private double[][]	a Coefficients
private static short	N Number of points.
private BivariateRealFunction	partialDerivativeX First partial derivative along x.
private BivariateRealFunction	partialDerivativeXX Second partial derivative along x.
private BivariateRealFunction	partialDerivativeXY Second crossed partial derivative.
private BivariateRealFunction	partialDerivativeY First partial derivative along y.
private BivariateRealFunction	partialDerivativeYY Second partial derivative along y.

Constructor Summary

BicubicSplineFunction(double[] a)
Simple constructor.

Method Summary

private double	apply(double[] pX, double[] pY, double[][] coeff) Compute the value of the bicubic polynomial.
private void	computePartialDerivatives() Compute all partial derivatives functions.
BivariateRealFunction	partialDerivativeX()
BivariateRealFunction	partialDerivativeXX()
BivariateRealFunction	partialDerivativeXY()
BivariateRealFunction	partialDerivativeY()
BivariateRealFunction	partialDerivativeYY()
double	value(double x, double y) Compute the value for the function.

Methods inherited from class java.lang.Object

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

Field Detail

N

private static final short N

Number of points.

See Also:

Constant Field Values

a

private final double[][] a

Coefficients

partialDerivativeX

private BivariateRealFunction partialDerivativeX

First partial derivative along x.

partialDerivativeY

private BivariateRealFunction partialDerivativeY

First partial derivative along y.

partialDerivativeXX

private BivariateRealFunction partialDerivativeXX

Second partial derivative along x.

partialDerivativeYY

private BivariateRealFunction partialDerivativeYY

Second partial derivative along y.

partialDerivativeXY

private BivariateRealFunction partialDerivativeXY

Second crossed partial derivative.

Constructor Detail

BicubicSplineFunction

public BicubicSplineFunction(double[] a)

Simple constructor.

Parameters:

a - Spline coefficients

Method Detail

value

public double value(double x,
                    double y)

Compute the value for the function.

Specified by:

value in interface BivariateRealFunction

Parameters:

x - Abscissa for which the function value should be computed.

y - Ordinate for which the function value should be computed.

Returns:

the value.

apply

private double apply(double[] pX,
                     double[] pY,
                     double[][] coeff)

Compute the value of the bicubic polynomial.

Parameters:

pX - Powers of the x-coordinate.

pY - Powers of the y-coordinate.

coeff - Spline coefficients.

Returns:

the interpolated value.

partialDerivativeX

public BivariateRealFunction partialDerivativeX()

Returns:

the partial derivative wrt x.

partialDerivativeY

public BivariateRealFunction partialDerivativeY()

Returns:

the partial derivative wrt y.

partialDerivativeXX

public BivariateRealFunction partialDerivativeXX()

Returns:

the second partial derivative wrt x.

partialDerivativeYY

public BivariateRealFunction partialDerivativeYY()

Returns:

the second partial derivative wrt y.

partialDerivativeXY

public BivariateRealFunction partialDerivativeXY()

Returns:

the second partial cross-derivative.

computePartialDerivatives

private void computePartialDerivatives()

Compute all partial derivatives functions.