math.numerics
Class ODEMultistepSolver

java.lang.Object
  math.numerics.ODEMultistepSolver

All Implemented Interfaces:

ODEAdaptiveSolver, ODESolver

public class ODEMultistepSolver
extends java.lang.Object
implements ODEAdaptiveSolver

ODEMultistepSolver performs multiple ODE steps so that a uniform step size is maintained.

Version:

1.0

Author:

Wolfgang Christian

Field Summary

static int	CONVERGE_ERROR
static int	NO_ERROR

Constructor Summary

ODEMultistepSolver(ODE ode)
Constructs an ODEMultiStep ODE solver for a system of ordinary differential equations.

Method Summary

double	getStepSize() Gets the step size.
double	getTolerance() Gets the tolerance of the adaptive ODE sovler.
void	initialize(double stepSize) Initializes the ODE solver.
static ODEAdaptiveSolver	MultistepRK45(ODE ode) A factory method that creates a multisetp solver using the RK45 engine.
void	setStepSize(double stepSize) Sets the fixed step size.
void	setTolerance(double tol) Sets the tolerance of the adaptive ODE sovler.
double	step() Steps (advances) the differential equations by the stepSize.

Methods inherited from class java.lang.Object

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

Field Detail

NO_ERROR

public static final int NO_ERROR

See Also:

Constant Field Values

CONVERGE_ERROR

public static final int CONVERGE_ERROR

See Also:

Constant Field Values

Constructor Detail

ODEMultistepSolver

public ODEMultistepSolver(ODE ode)

Constructs an ODEMultiStep ODE solver for a system of ordinary differential equations. The default ODESolver is RK45. Other solvers can be selected using factory methods.

Parameters:

ode -

Method Detail

MultistepRK45

public static ODEAdaptiveSolver MultistepRK45(ODE ode)

A factory method that creates a multisetp solver using the RK45 engine.

Parameters:

ode - ODE

Returns:

ODESolver

setTolerance

public void setTolerance(double tol)

Sets the tolerance of the adaptive ODE sovler.

Specified by:

setTolerance in interface ODEAdaptiveSolver

Parameters:

tol - the tolerance

getTolerance

public double getTolerance()

Gets the tolerance of the adaptive ODE sovler.

Specified by:

getTolerance in interface ODEAdaptiveSolver

Returns:

step

public 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 affineTransform the end of the solution step if desired tolerance was reached.

Specified by:

step in interface ODESolver

Returns:

the actual step

initialize

public void initialize(double stepSize)

Initializes the ODE solver. Temporary arrays may be allocated within the ODE solver.

Specified by:

initialize in interface ODESolver

Parameters:

stepSize -

setStepSize

public void setStepSize(double stepSize)

Sets the fixed step size. Multi-step solvers will perform one or more internal steps in order to perform a step with the given size.

Specified by:

setStepSize in interface ODESolver

Parameters:

stepSize -

getStepSize

public double getStepSize()

Gets the step size. The step size is the fixed step size, not the size of the ODEAdaptiveSolver steps that are combined into a single step.

Specified by:

getStepSize in interface ODESolver

Returns:

the step size