org.opensourcephysics.numerics
Class CubicSpline

java.lang.Object
  org.opensourcephysics.numerics.CubicSpline

All Implemented Interfaces:

Function

public class CubicSpline
extends java.lang.Object
implements Function

Class description

Constructor Summary

CubicSpline(double[] xdata, double[] ydata)
Constructs a natural CubicSpline interpolating function from the given data.

CubicSpline(double[] xdata, double[] ydata, double startDyDx, double endDyDx)
Constructs a constrained CubicSpline interpolating function from the given data.

Method Summary

double	evaluate(double x) Computes the interpolated y value for a given x value.
Function	firstDerivative()
Function	secondDerivative()
void	update(double[] xdata, double[] ydata) Update the natural spline data and recompute the coefficients.
void	update(double[] xdata, double[] ydata, double startDyDx, double endDyDx) Update the constrained spline data and recompute the coefficients.

Methods inherited from class java.lang.Object

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

Constructor Detail

CubicSpline

public CubicSpline(double[] xdata,
                   double[] ydata)

Constructs a natural CubicSpline interpolating function from the given data. X data array must be sorted in increasing or decreasing value. The checkSorting method in the Util package can be used to check the sorting of an array.

Parameters:

xdata - double[]

ydata - double[]

CubicSpline

public CubicSpline(double[] xdata,
                   double[] ydata,
                   double startDyDx,
                   double endDyDx)

Constructs a constrained CubicSpline interpolating function from the given data. X data array must be sorted in increasing or decreasing value. The checkSorting method in the Util package can be used to check the sorting of an array.

Parameters:

xdata - double[]

ydata - double[]

startDyDx - double derivative at 0

endDyDx - double derivative at n-1

Method Detail

update

public void update(double[] xdata,
                   double[] ydata,
                   double startDyDx,
                   double endDyDx)

Update the constrained spline data and recompute the coefficients.

Parameters:

xdata -

ydata -

update

public void update(double[] xdata,
                   double[] ydata)

Update the natural spline data and recompute the coefficients.

Parameters:

xdata -

ydata -

evaluate

public double evaluate(double x)

Computes the interpolated y value for a given x value.

Specified by:

evaluate in interface Function

Parameters:

x -

Returns:

interpolated y value.

firstDerivative

public Function firstDerivative()

secondDerivative

public Function secondDerivative()