org.micropsi.nodenet
Class Gate

java.lang.Object
  org.micropsi.nodenet.Gate

public final class Gate

extends java.lang.Object

The links between NetEntitys originate from Gates. Gates have parameters that affect the way activation is propagated, similar to neurons in connectionist networks. The output of a gate is calculated by one of the functions defined in the class GateOutputFunctions. These functions may make use of the parameters activation, maximum, minimum and the "unbound" parameter theta, the latter with different semantics for each output function.
Whatever the output function may calculated, it's value is then multiplied by the gate parameter "ampfactor", the result again checked to be between minimum and maximum.

Additionaly, gates calculate the decay of the attached link's weights whenever these links are used.

Every gate has a type that MUST be unique within one entity.

Constructor Summary

protected

Gate(int type, NetEntity center, int decayType) Constructor for the gate, setting it's type, center-entity and the decay type of the links.

Method Summary

protected void	addLink(Link link) Adds a link to the gate.
protected void	calculateDecays(long netstep) Calculates the decay for all attached links.
protected boolean	confirmActivation() Confirms the current activation as authoritative during the next cycle
protected void	deleteLink(Link link) Deletes a link from the gate.
protected void	destroy() Frees as many references as possible to avoid too much gc activity
protected double	getActivation() Returns the gate's "raw" activation, without having it multiplied or checked it against anything.
double	getAmpfactor() Returns the ampfactor.
double	getConfirmedActivation() Returns the confirmed activation of this gate.
OutputFunctionParameter[]	getCurrentOutputFunctionParameters() Returns the current parameters of the output function.
int	getDecayCalculatorType() Returns the decayCalculatorType.
double	getGateFactor() Returns the gateFactor.
protected long	getLastDecayCalculation()
Link	getLinkAt(int n) Returns the nth link attached to this gate
java.util.Iterator	getLinks() Returns an iterator with instances of Link.
Link	getLinkTo(java.lang.String entityID, int slot) Returns a specific link
double	getMaximum() Returns the maximum output of the gate.
double	getMinimum() Returns the minimum output of the (active) gate
NetEntity	getNetEntity() Returns the gate's "center" entity, the entity that the gate belongs to.
int	getNumberOfLinks() Returns the number of links
OutputFunctionIF	getOutputFunction() Retuns the type of the output function used in this gate
double	getOutputFunctionParameter(java.lang.String parameterName) Returns the current value of a given output function parameter
int	getType() Returns the type
boolean	hasLinks() Returns true if there are links at this gate
boolean	isActive() Checks if the gate is "active", that is: if the gate's activation ist !
protected void	setActivation(double activation) Sets the activation.
protected void	setAmpfactor(double ampfactor) Sets the ampfactor.
protected void	setConfirmedActivation(double activation) Sets the confirmed activation.
protected void	setDecayCalculatorType(int decayCalculatorType) Sets the decayCalculatorType.
protected void	setGateFactor(double factor) Sets the gate factor.
protected void	setLastDecayCalculation(long lastDecayCalculation) Sets the lastDecayCalculation.
protected void	setMaximum(double maximum) Sets the maximum.
protected void	setMinimum(double minimum) Method setMinimum.
protected void	setOutputFunction(OutputFunctionIF function) Sets the output function.
protected void	setOutputFunctionParameter(java.lang.String parameterName, double value) Sets one of tge output function's constant parameters.
protected void	setOutputFunctionParameters(OutputFunctionParameter[] ofParams) Sets all output function parameters at once.
java.lang.String	toString()
protected void	unlinkCompletely() Unlinks the entity completely - for cleaning up or to prepare the entity for deletion.

Methods inherited from class java.lang.Object

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

Constructor Detail

Gate

protected Gate(int type,
               NetEntity center,
               int decayType)

Constructor for the gate, setting it's type, center-entity and the decay type of the links.

Parameters:

type - the gate's type

center - the NetEntity that the gate belongs to

decayType - the type of decay to be applied

Method Detail

getNetEntity

public NetEntity getNetEntity()

Returns the gate's "center" entity, the entity that the gate belongs to.

Returns:

NetEntity the entity

addLink

protected void addLink(Link link)

Adds a link to the gate. This method is low-level and does not care for the net's integrity in any way.

Parameters:

link - the link to be added to the gate.

deleteLink

protected void deleteLink(Link link)

Deletes a link from the gate. (Must be the instance of the link!) This method is low-level and does not care for integrity.

Parameters:

link - the link to be deleted

unlinkCompletely

protected void unlinkCompletely()
                         throws NetIntegrityException

Unlinks the entity completely - for cleaning up or to prepare the entity for deletion. This is a high-level method and ensures that the link references are dropped correctly by the gate and the linked slots.

Throws:

NetIntegrityException - if there are bad links at this gate.

getLinks

public java.util.Iterator getLinks()

Returns an iterator with instances of Link. Do not call remove() or the net's integrity will be violated badly.

Returns:

Iterator the links

getLinkAt

public Link getLinkAt(int n)

Returns the nth link attached to this gate

Parameters:

n - the index of the link

Returns:

Link the link or null if there is no nth link

getLinkTo

public Link getLinkTo(java.lang.String entityID,
                      int slot)
               throws NetIntegrityException

Returns a specific link

Parameters:

entityID - the ID of the linked entity

slot - the slot where the link ends

Returns:

Link the link or null if there is no such link

Throws:

NetIntegrityException - if the requested link is bad

setGateFactor

protected void setGateFactor(double factor)

Sets the gate factor.

Parameters:

factor - the gateFactor.

getGateFactor

public double getGateFactor()

Returns the gateFactor.

Returns:

double the gateFactor

getActivation

protected double getActivation()

Returns the gate's "raw" activation, without having it multiplied or checked it against anything. This should only be used for transporting or saving the net's state, not for any logical operation!

Returns:

double the raw activation of the gate.

getConfirmedActivation

public double getConfirmedActivation()

Returns the confirmed activation of this gate.

Returns:

double

confirmActivation

protected boolean confirmActivation()

Confirms the current activation as authoritative during the next cycle

isActive

public boolean isActive()

Checks if the gate is "active", that is: if the gate's activation ist != 0

Returns:

boolean true if the gate is active

calculateDecays

protected void calculateDecays(long netstep)
                        throws NetIntegrityException

Calculates the decay for all attached links. This actually changes the weights of the links!

Parameters:

netstep -

Throws:

NetIntegrityException

getType

public int getType()

Returns the type

Returns:

int the type

getAmpfactor

public double getAmpfactor()

Returns the ampfactor.

Returns:

double the ampfactor

getDecayCalculatorType

public int getDecayCalculatorType()

Returns the decayCalculatorType.

Returns:

int

getOutputFunction

public OutputFunctionIF getOutputFunction()

Retuns the type of the output function used in this gate

Returns:

int

getMaximum

public double getMaximum()

Returns the maximum output of the gate.

Returns:

double

getMinimum

public double getMinimum()

Returns the minimum output of the (active) gate

Returns:

double

setActivation

protected void setActivation(double activation)

Sets the activation.

Parameters:

activation - The activation to set

setConfirmedActivation

protected void setConfirmedActivation(double activation)

Sets the confirmed activation. This should only be called for persistency reasons!

Parameters:

activation - The activation to set

setAmpfactor

protected void setAmpfactor(double ampfactor)

Sets the ampfactor.

Parameters:

ampfactor - The ampfactor to set

setDecayCalculatorType

protected void setDecayCalculatorType(int decayCalculatorType)

Sets the decayCalculatorType.

Parameters:

decayCalculatorType - The decayCalculatorType to set

setOutputFunction

protected void setOutputFunction(OutputFunctionIF function)

Sets the output function.

Parameters:

function - The function to be used.

setMaximum

protected void setMaximum(double maximum)

Sets the maximum.

Parameters:

maximum - The maximum to set

getCurrentOutputFunctionParameters

public OutputFunctionParameter[] getCurrentOutputFunctionParameters()

Returns the current parameters of the output function.

Returns:

an array with parameters, filled with current values. Never null.

getOutputFunctionParameter

public double getOutputFunctionParameter(java.lang.String parameterName)

Returns the current value of a given output function parameter

Parameters:

parameterName - the name of the parameter

Returns:

the current value of the parameter

Throws:

java.lang.IllegalArgumentException - if the output function of this gate does not support the given parameter

setOutputFunctionParameter

protected void setOutputFunctionParameter(java.lang.String parameterName,
                                          double value)

Sets one of tge output function's constant parameters.

Parameters:

parameterName - the name of the parameter

value - the new value

Throws:

java.lang.IllegalArgumentException - if the output function does not have this parameter

setOutputFunctionParameters

protected void setOutputFunctionParameters(OutputFunctionParameter[] ofParams)

Sets all output function parameters at once. This method does not check wheter the gate's output function supports the given parameters.

Parameters:

ofParams - the parameters.

setMinimum

protected void setMinimum(double minimum)

Method setMinimum.

Parameters:

minimum -

getNumberOfLinks

public int getNumberOfLinks()

Returns the number of links

Returns:

int

hasLinks

public boolean hasLinks()

Returns true if there are links at this gate

Returns:

boolean

getLastDecayCalculation

protected long getLastDecayCalculation()

Returns:

long

setLastDecayCalculation

protected void setLastDecayCalculation(long lastDecayCalculation)

Sets the lastDecayCalculation.

Parameters:

lastDecayCalculation - The lastDecayCalculation to set

toString

public java.lang.String toString()

See Also:

Object.toString()

destroy

protected void destroy()

Frees as many references as possible to avoid too much gc activity