javax.robotics.ode
Class RungeKutta4th2

java.lang.Object
  javax.robotics.ode.Euler2
      javax.robotics.ode.RungeKutta4th2

All Implemented Interfaces:

DerivableFunction2, Solver2

public class RungeKutta4th2
extends Euler2

This class implements forward RungeKutta4th integration method for systems of two first order differential equations.

x''=f(x, x') with x(0)=x0, x'(0)= y0, is equivalent to system of two first order of differential equation:
y' = f(x, y)
x' = y
with x(0)=x0, y(0)= y0

Since:

1.0.3

Version:

09/11/2005

Author:

Carmine Lia

Field Summary

Fields inherited from interface javax.robotics.ode.Solver2

startTime

Constructor Summary

RungeKutta4th2(double dt, RVector initialConditionPosition, RVector initialConditionVelocity)
Defines RungeKutta4th numerical integration for x'' = f(x, x') as system of two first order differential equation.

RungeKutta4th2(double dt, RVector initialConditionPosition, RVector initialConditionVelocity, DerivableFunction2 target)
Defines RungeKutta4th numerical integration for x'' = f(x, x') as system of two first order differential equation.

Method Summary

void	step(RVector position, RVector velocity) Computes step integration from time t to t+dt of x'' = f(x, x').

Methods inherited from class javax.robotics.ode.Euler2

getInitialConditionPosition, getInitialConditionVelocity, getLastValuePosition, getLastValueVelocity, getSampleTime, getTime, resetTime, setInitialConditionPosition, setInitialConditionVelocity, setSampleTime, setTargetFunction, xDot2

Methods inherited from class java.lang.Object

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

Constructor Detail

RungeKutta4th2

public RungeKutta4th2(double dt,
                      RVector initialConditionPosition,
                      RVector initialConditionVelocity)

Defines RungeKutta4th numerical integration for x'' = f(x, x') as system of two first order differential equation.

Parameters:

dt - time interval of integration [sec]

initialConditionPosition - position at time zero x(0).

initialConditionVelocity - velocity at time zero x'(0).

RungeKutta4th2

public RungeKutta4th2(double dt,
                      RVector initialConditionPosition,
                      RVector initialConditionVelocity,
                      DerivableFunction2 target)

Defines RungeKutta4th numerical integration for x'' = f(x, x') as system of two first order differential equation.

Parameters:

dt - time interval of integration [sec]

initialConditionPosition - position at time zero x(0).

initialConditionVelocity - velocity at time zero x'(0).

target - differential equation to be integrated

Method Detail

step

public void step(RVector position,
                 RVector velocity)

Description copied from interface: Solver2

Computes step integration from time t to t+dt of x'' = f(x, x'). The params last value position and velocity are modified.

Specified by:

step in interface Solver2

Overrides:

step in class Euler2

Parameters:

position - x argument of f(x, x')

velocity - x' argument of f(x, x')