javax.robotics.ode
Class Euler

java.lang.Object
  javax.robotics.ode.Euler

All Implemented Interfaces:

DerivableFunction, Solver

Direct Known Subclasses:

Heun, RungeKutta4th

public class Euler
extends java.lang.Object
implements Solver, DerivableFunction

This class implements forward Euler integration method.

Since:

1.0.0

Version:

09/11/2005

Author:

Carmine Lia

Field Summary

Fields inherited from interface javax.robotics.ode.Solver

startTime

Constructor Summary

Euler(double dt, RVector initialCondition, DerivableFunction target)
Defines numerical integration for x' = f(x) differential equation.

Method Summary

RVector	getInitialCondition() Gets the initial condition for position x(0).
RVector	getLastValue() Gets the current value of position x computed by step function.
double	getSampleTime() Gets the interval of integration.
double	getTime() Gets current time of integration.
void	setInitialCondition(RVector initialCondition) Sets the initial condition for position x(0) = x0.
void	setSampleTime(double dt) Sets the interval of integration.
void	step(RVector x) Computes step integration from time t to t+dt of x' = f(x).
RVector	xDot(RVector x) Derivate prime function x' = f(x).

Methods inherited from class java.lang.Object

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

Constructor Detail

Euler

public Euler(double dt,
             RVector initialCondition,
             DerivableFunction target)

Defines numerical integration for x' = f(x) differential equation.

Parameters:

dt - time interval of integration [sec]

initialCondition - initial condition at time zero x(0).

target - differential equation to be integrated

Method Detail

setSampleTime

public final void setSampleTime(double dt)

Description copied from interface: Solver

Sets the interval of integration.

Specified by:

setSampleTime in interface Solver

Parameters:

dt - interval [sec]

getSampleTime

public final double getSampleTime()

Description copied from interface: Solver

Gets the interval of integration.

Specified by:

getSampleTime in interface Solver

Returns:

the dt interval [sec]

setInitialCondition

public final void setInitialCondition(RVector initialCondition)

Description copied from interface: Solver

Sets the initial condition for position x(0) = x₀.

Specified by:

setInitialCondition in interface Solver

getInitialCondition

public final RVector getInitialCondition()

Description copied from interface: Solver

Gets the initial condition for position x(0).

Specified by:

getInitialCondition in interface Solver

Returns:

the initialCondition

getLastValue

public final RVector getLastValue()

Description copied from interface: Solver

Gets the current value of position x computed by step function.

Specified by:

getLastValue in interface Solver

Returns:

the current position.

getTime

public final double getTime()

Description copied from interface: Solver

Gets current time of integration.

Specified by:

getTime in interface Solver

Returns:

the current time [sec]

step

public void step(RVector x)

Description copied from interface: Solver

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

Specified by:

step in interface Solver

Parameters:

x - argument of f(x)

xDot

public RVector xDot(RVector x)

Description copied from interface: DerivableFunction

Derivate prime function x' = f(x).

Specified by:

xDot in interface DerivableFunction

Parameters:

x - indipendent variable

Returns:

derivate prime