ca.nengo.dynamics.impl

Class RK45Integrator

java.lang.Object

ca.nengo.dynamics.impl.RK45Integrator

All Implemented Interfaces:

Integrator, java.io.Serializable, java.lang.Cloneable

public class RK45Integrator
extends java.lang.Object
implements Integrator

A variable-timestep Integrator, which uses the Dormand-Prince 4th and 5th-order Runge-Kutta formulae.

This code is adapted from a GPL Octave implementation by Marc Compere (see http://users.powernet.co.uk/kienzle/octave/matcompat/scripts/ode_v1.11/ode45.m)

See also Dormand & Prince, 1980, J Computational and Applied Mathematics 6(1), 19-26.

TODO: should re-use initial time step estimate from last integration if available

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
RK45Integrator() Uses default error tolerance of 1e-6
RK45Integrator(float tolerance)

Method Summary

Methods

Modifier and Type	Method and Description
Integrator	clone()
float	getTolerance()
TimeSeries	integrate(DynamicalSystem system, TimeSeries input) Integrates the given system over the time span defined by the input time series.
void	setTolerance(float tolerance)

Methods inherited from class java.lang.Object

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

Constructor Detail

RK45Integrator

public RK45Integrator(float tolerance)

Parameters:

tolerance - Error tolerance

RK45Integrator

public RK45Integrator()

Uses default error tolerance of 1e-6

Method Detail

getTolerance

public float getTolerance()

Returns:

Error tolerance

setTolerance

public void setTolerance(float tolerance)

Parameters:

tolerance - Error tolerance

integrate

public TimeSeries integrate(DynamicalSystem system,
                   TimeSeries input)

Description copied from interface: Integrator

Integrates the given system over the time span defined by the input time series.

Specified by:

integrate in interface Integrator

Parameters:

system - The DynamicalSystem to solve.

input - Input vector to the system, defined at the desired start and end times of integration, and optionally at times in between. The way in which the integrator interpolates between inputs at different times is decided by the Integrator implementation.

Returns:

Time series of output vector

See Also:

Integrator.integrate(ca.nengo.dynamics.DynamicalSystem, ca.nengo.util.TimeSeries)

clone

public Integrator clone()
                 throws java.lang.CloneNotSupportedException

Specified by:

clone in interface Integrator

Overrides:

clone in class java.lang.Object

Returns:

cloned Integrator

Throws:

java.lang.CloneNotSupportedException - is clone operation fails