## 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 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.

Copyright (c) 2003-2013 Apache Software Foundation