uk.ac.ed.ph.integrator
Class DataPoint

java.lang.Object
  uk.ac.ed.ph.integrator.DataDerivative
      uk.ac.ed.ph.integrator.DataPoint

All Implemented Interfaces:

Cloneable

public class DataPoint
extends DataDerivative

Class to hold a single DataPoint consisting of an x coordinate and a array of y coordinates for use in integrator methods.

Field Summary

Fields inherited from class uk.ac.ed.ph.integrator.DataDerivative

fmt, x, y

Constructor Summary

DataPoint()
Default constrcuor, set x=0 and y[] array to null

DataPoint(double x, double[] y)
Constructor to form a DataPoint from a x coordinate and y array

DataPoint(int size)
Constrcuor to form a DataPoint with specified size of y array, and all values are set to zero

Method Summary

void	addToX(double step) Method add to the current value of the X.
void	addToY(int i, double delta) Method to add to a single y element.
DataPoint	clone() Method to return a clone of the current DataPoint including a copy of the y array.
double	error(DataPoint p) The default error between two DataPoints, currently set as the normalsied square error
DataPoint	eulerStep(DataDerivative delta, double step) Method to for a new DataPoint by propagating the current point a specified distance (step), with the differentials in delta using the simple Euler scheme
String	formatPoint() Method to format a point as a String for file output with x value and each y[] element seperated by a space.
double	maximumError(DataPoint p) Method to calcuate the absolute maximum error between elemenst of the y paramter array
void	setDefaultError(int code) Method to set the default error
double	squareError(DataPoint p) Calcualte the normalsied square error between the current DataPoint as the specified DataPoint
DataPoint	weightedStep(DataDerivative[] delta, double[] w, double step) Method to a new DataPoint be propagating the current DataPoint by a weighted step.

Methods inherited from class uk.ac.ed.ph.integrator.DataDerivative

getX, getY, getY, setFormatString, setX, setY, setY, size, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

DataPoint

public DataPoint()

Default constrcuor, set x=0 and y[] array to null

DataPoint

public DataPoint(double x,
                 double[] y)

Constructor to form a DataPoint from a x coordinate and y array

Parameters:

x - the x value

y - the y data array

DataPoint

public DataPoint(int size)

Constrcuor to form a DataPoint with specified size of y array, and all values are set to zero

Parameters:

size - size of y variable array

Method Detail

clone

public DataPoint clone()

Method to return a clone of the current DataPoint including a copy of the y array.

Overrides:

clone in class DataDerivative

Returns:

DataPoint clone of current DataPoint

addToX

public void addToX(double step)

Method add to the current value of the X.

Parameters:

step - the value to ve added.

addToY

public void addToY(int i,
                   double delta)

Method to add to a single y element.

Parameters:

i - the element to be set

delta - the valeu to be added.

formatPoint

public String formatPoint()

Method to format a point as a String for file output with x value and each y[] element seperated by a space.

Returns:

String formatted String.

squareError

public double squareError(DataPoint p)

Calcualte the normalsied square error between the current DataPoint as the specified DataPoint

Parameters:

p - the specified DataPoint

Returns:

double Normalsied square error.

maximumError

public double maximumError(DataPoint p)

Method to calcuate the absolute maximum error between elemenst of the y paramter array

Parameters:

p - the spefied DataPoint

Returns:

double the absolute maximun error (not normalsied)

setDefaultError

public void setDefaultError(int code)

Method to set the default error

error

public double error(DataPoint p)

The default error between two DataPoints, currently set as the normalsied square error

Parameters:

p - the specified DataPoint

Returns:

double the default error

eulerStep

public DataPoint eulerStep(DataDerivative delta,
                           double step)

Method to for a new DataPoint by propagating the current point a specified distance (step), with the differentials in delta using the simple Euler scheme

Parameters:

delta - the specified differential

step - the step distance.

weightedStep

public DataPoint weightedStep(DataDerivative[] delta,
                              double[] w,
                              double step)

Method to a new DataPoint be propagating the current DataPoint by a weighted step.

Parameters:

delta - array of differntials

w - the wieght of the corresponding differentials (assumed to sum to 1.0)

step - the step

Returns:

DataPoint the wiegthed steped DataPoint.