org.opensourcephysics.numerics
Class AbstractODESolver

java.lang.Object
  org.opensourcephysics.numerics.AbstractODESolver

All Implemented Interfaces:

ODESolver

Direct Known Subclasses:

Butcher5, Euler, EulerRichardson, Fehlberg8, Heun3, LeapFrog, Ralston2, RK4, Verlet

public abstract class AbstractODESolver

extends java.lang.Object

implements ODESolver

AbstractODE provides a common superclass for ODESolvers.

Field Summary

protected int	numEqn
protected ODE	ode
protected double	stepSize

Constructor Summary

AbstractODESolver(ODE _ode)
Constructs the ODESolver for a system of ordinary differential equations.

Method Summary

static ODESolver	createODESolver(ODE ode, java.lang.String solverName) A factory method that creates an ODESolver using a name.
double	getStepSize() Gets the step size.
void	initialize(double _stepSize) Initializes the ODE solver.
void	setStepSize(double _stepSize) Sets the step size.
abstract double	step() Steps (advances) the differential equations by the stepSize.

Methods inherited from class java.lang.Object

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

Field Detail

stepSize

protected double stepSize

numEqn

protected int numEqn

ode

protected ODE ode

Constructor Detail

AbstractODESolver

public AbstractODESolver(ODE _ode)

Constructs the ODESolver for a system of ordinary differential equations.

Parameters:

_ode - the system of differential equations.

Method Detail

step

public abstract double step()

Steps (advances) the differential equations by the stepSize. The ODESolver invokes the ODE's getRate method to obtain the initial state of the system. The ODESolver then advances the solution and copies the new state into the state array at the end of the solution step.

Specified by:

step in interface ODESolver

Returns:

the step size

setStepSize

public void setStepSize(double _stepSize)

Sets the step size. The step size remains fixed in this algorithm

Specified by:

setStepSize in interface ODESolver

Parameters:

_stepSize -

initialize

public void initialize(double _stepSize)

Initializes the ODE solver. The rate array is allocated. The number of differential equations is determined by invoking getState().length on the ODE.

Specified by:

initialize in interface ODESolver

Parameters:

_stepSize -

getStepSize

public double getStepSize()

Gets the step size. The stepsize is constant in this algorithm

Specified by:

getStepSize in interface ODESolver

Returns:

the step size

createODESolver

public static ODESolver createODESolver(ODE ode,
                                        java.lang.String solverName)

A factory method that creates an ODESolver using a name.

Parameters:

ode - ODE

solverName - String the name of the algorithm

Returns:

ODESolver