org.omegahat.Numerics.Optimizers
Class Optimizer

java.lang.Object
  |
  +--org.omegahat.Numerics.Optimizers.OptimizerBasic
        |
        +--org.omegahat.Numerics.Optimizers.Optimizer

All Implemented Interfaces:

OptimizerIterator

public class Optimizer

extends OptimizerBasic

The standard optimizer class. Objects from this class iterate by calling the initialize, refine, and wrapup methods of an OptimizerAlgorithm object.

Each iteration is preceded by notifying all the listeners registered with the optimizer object. By default, this includes a DefaultListener that checks the number of iterations and some standard numeric conditions for convergence.

This class extends OptimizerBasic, which provides the iteration, but does not implement event listeners for control. If you want to handle control by a mechanism other than listeners, subclass that class or otherwise implement the OptimizerIterator interface.

Field Summary

static int	BACKGROUND
protected BackgroundTaskManager	backgroundManager This manager takes care of the background, or non-blocking, listeners.
static int	COMPLETION
protected java.util.EventListener	defaultListener
static int	INFORMATION
static int	INITIALIZATION symbolic constants to index the array of listeners.
static int	ITERATION
protected java.util.Vector[]	listeners An array of objects, each of which is a list of listeners of a particular type.
static int	NUM_LISTENER_VECTORS

Fields inherited from class org.omegahat.Numerics.Optimizers.OptimizerBasic

algorithm, current, objective, state

Fields inherited from interface org.omegahat.Numerics.Optimizers.OptimizerIterator

CONTINUE, CONVERGED, EXCEPTION, NUMERIC_PROBLEM, TOO_MANY_STEPS

Constructor Summary

Optimizer(OptimizerAlgorithm fitter)

Optimizer(OptimizerAlgorithm fitter, ModelObjective model, double[] start)

Optimizer(OptimizerAlgorithm fitter, ModelPoint start)

Method Summary

void	addBackgroundListener(IterationListener l)
void	addConvergedListener(IterationListener l) A listener to be called only on completion.
void	addInformationListener(IterationListener l) Add an information listener to be called on each step in the iteration.
void	addInitializationListener(IterationListener l) A listener to be called only on initialization.
void	addIterationListener(IterationListener l) Add a listener to be called at each step in the iteration with the option of controlling the convergence.
void	addListener(java.util.EventListener l) Add a listener to the optimizer.
boolean	addListener(java.util.EventListener l, int type) A listener added with a computed type, which should be one of the pre-defined static constants in this class.
void	addStepListener(IterationListener l) A listener to be called only after each iteration step.
BackgroundTaskManager	backgroundManager()
BackgroundTaskManager	backgroundManager(BackgroundTaskManager m)
BackgroundTaskManager	backgroundManager(BackgroundTaskManager m, boolean start)
boolean	continueIteration(OptimizerAlgorithm opt, ModelPoint values) Called after each iteration to test whether to continue.
java.util.EventListener	createDefaultListener() This must be a separate method so as to allow people to override it.
java.util.EventListener	dropListener() Drop the last iteration listener added.
java.util.EventListener	dropListener(java.util.EventListener l) Drop this listener object.
ModelPoint	eval() Carry out the iteration.
java.util.EventListener	getDefaultListener() Accessor for defaultListener field
java.util.Vector[]	getListeners()
boolean	hasListener(java.util.EventListener l, int type) Check whether this object is a listener of the given type.
ModelPoint	initialize(ModelPoint initialValue) Initialize the optimizer with the values supplied.
void	make() Make the structures in the object.
void	notifyBackgroundListeners(IterationEvent event) Notify all background listeners of the event.
void	notifyInformationListeners(IterationEvent ev) Notify all the information listeners of the event.
void	notifyListeners(IterationEvent event) Notify all listeners of the given event.
void	notifyListeners(ModelPoint values, int type) Notify all listeners of the given type of an IterationEvent containing the specified values for the model.
java.util.EventListener	setDefaultListener() Initialize the default listener to an object from the DefaultListener class.
java.util.EventListener	setDefaultListener(java.util.EventListener value) Accessor for setting defaultListener field
java.util.Vector[]	setListeners(java.util.Vector[] v)

Methods inherited from class org.omegahat.Numerics.Optimizers.OptimizerBasic

eval, getAlgorithm, getCurrent, getObjective, getState, setAlgorithm, setCurrent, setObjective, setState

Methods inherited from class java.lang.Object

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

Field Detail

INITIALIZATION

public static final int INITIALIZATION

symbolic constants to index the array of listeners.

COMPLETION

public static final int COMPLETION

ITERATION

public static final int ITERATION

BACKGROUND

public static final int BACKGROUND

INFORMATION

public static final int INFORMATION

NUM_LISTENER_VECTORS

public static final int NUM_LISTENER_VECTORS

listeners

protected java.util.Vector[] listeners

An array of objects, each of which is a list of listeners of a particular type.

backgroundManager

protected BackgroundTaskManager backgroundManager

This manager takes care of the background, or non-blocking, listeners.

defaultListener

protected java.util.EventListener defaultListener

Constructor Detail

Optimizer

public Optimizer(OptimizerAlgorithm fitter)

Optimizer

public Optimizer(OptimizerAlgorithm fitter,
                 ModelPoint start)

Optimizer

public Optimizer(OptimizerAlgorithm fitter,
                 ModelObjective model,
                 double[] start)

Method Detail

make

public void make()

Make the structures in the object.

Called from each of the constructors. Sets up the listener structures and adds a DefaultListener object to the iteration listeners.

initialize

public ModelPoint initialize(ModelPoint initialValue)

Initialize the optimizer with the values supplied.

Iteration listeners that implement CounterListener will have their count reset to 0.

Note that this method does not call the initializer of the optimization algorithm. Whether the algorithm should be reset between one iteration and the next is a matter of strategy, and should not be forced on the user. To reset the algorithm, use getAlgorithm().initialize(initialValue, opt)

Overrides:

initialize in class OptimizerBasic

createDefaultListener

public java.util.EventListener createDefaultListener()

This must be a separate method so as to allow people to override it.

eval

public ModelPoint eval()
                throws java.lang.Exception

Carry out the iteration.

Overrides:

eval in class OptimizerBasic

notifyListeners

public void notifyListeners(ModelPoint values,
                            int type)

Notify all listeners of the given type of an IterationEvent containing the specified values for the model.

notifyListeners

public void notifyListeners(IterationEvent event)

Notify all listeners of the given event.

notifyInformationListeners

public void notifyInformationListeners(IterationEvent ev)

Notify all the information listeners of the event.

notifyBackgroundListeners

public void notifyBackgroundListeners(IterationEvent event)

Notify all background listeners of the event.

The actual performance of the corresponding tasks is the responsibility of an object of class BackgroundTaskManager.

continueIteration

public boolean continueIteration(OptimizerAlgorithm opt,
                                 ModelPoint values)

Description copied from class: OptimizerBasic

Called after each iteration to test whether to continue.

The basic method only checks the state of the optimizer, which must have been set by some other computation. In the subclass OptimizerNotifier the corresponding method calls all the iteration listeners. By default these include a counter that exits when too many iterations have taken place. The algorithm will likely add listener(s) of its own, to detect successful convergence.

Overrides:

continueIteration in class OptimizerBasic

addListener

public void addListener(java.util.EventListener l)

Add a listener to the optimizer.

The listeners will be called once on startup and again after each iterative step of refinement. In other words, the listener gets to examine the optimization for each step, including the initial one.

The argument can be an instance of: InformationListener, IterationListener, or BackgroundListener.

addIterationListener

public void addIterationListener(IterationListener l)

Add a listener to be called at each step in the iteration with the option of controlling the convergence.

addInformationListener

public void addInformationListener(IterationListener l)

Add an information listener to be called on each step in the iteration.

addBackgroundListener

public void addBackgroundListener(IterationListener l)

addInitializationListener

public void addInitializationListener(IterationListener l)

A listener to be called only on initialization.

addConvergedListener

public void addConvergedListener(IterationListener l)

A listener to be called only on completion.

addStepListener

public void addStepListener(IterationListener l)

A listener to be called only after each iteration step.

addListener

public boolean addListener(java.util.EventListener l,
                           int type)

A listener added with a computed type, which should be one of the pre-defined static constants in this class.

hasListener

public boolean hasListener(java.util.EventListener l,
                           int type)

Check whether this object is a listener of the given type.

dropListener

public java.util.EventListener dropListener(java.util.EventListener l)

Drop this listener object.

dropListener

public java.util.EventListener dropListener()

Drop the last iteration listener added.

Returns the listener dropped, or null if there were none. When called after creating a standard optimizer (one that is an instance of class OptimizerBasic or its extensions), this drops the default listener, which checks for the number of iterations and some default convergence conditions.

getDefaultListener

public java.util.EventListener getDefaultListener()

Accessor for defaultListener field

setDefaultListener

public java.util.EventListener setDefaultListener(java.util.EventListener value)

Accessor for setting defaultListener field

setDefaultListener

public java.util.EventListener setDefaultListener()

Initialize the default listener to an object from the DefaultListener class.

getListeners

public java.util.Vector[] getListeners()

setListeners

public java.util.Vector[] setListeners(java.util.Vector[] v)

backgroundManager

public BackgroundTaskManager backgroundManager()

backgroundManager

public BackgroundTaskManager backgroundManager(BackgroundTaskManager m)

backgroundManager

public BackgroundTaskManager backgroundManager(BackgroundTaskManager m,
                                               boolean start)