edu.gtts.sautrela.wfsa.models
Class HMM

java.lang.Object
  edu.gtts.sautrela.wfsa.models.HMM

All Implemented Interfaces:

NdWFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>, WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

public class HMM
extends java.lang.Object
implements NdWFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Array version of Discrete Hidden Markov Model

Author:

mpenagar

Nested Class Summary

class	HMM.State
class	HMM.Symbol

Nested classes/interfaces inherited from interface edu.gtts.sautrela.wfsa.WFSA

WFSA.Factory

Field Summary

static WFSA.Factory

myFactory

Constructor Summary

HMM(org.xml.sax.InputSource is)
Creates a HMM using an XML description found via an InputSource

HMM(org.xml.sax.InputSource is, Alphabet<HMM.Symbol> alphabet)
Creates a HMM using a XML description found via an InputSource and using an existing Alphabet.

Method Summary

void	dumpTrainCounts() Dumps the trained data to the HMM.
Alphabet<HMM.Symbol>	getAlphabet() Returns the alphabet of the Model.
double	getFinProb(HMM.State state) Returns the probability of being final
HMM.State	getIniState() Returns the initial State
java.lang.String	getName() Returns the name of the Model.
DefaultTransition<HMM.State,HMM.Symbol>	getRandomTrans(HMM.State state) Returns a random transitions from a state
HMM.Symbol	getSymbolByName(java.lang.String name)
DefaultTransition<HMM.State,HMM.Symbol>[]	getTrans(HMM.State from) Returns all possible transitions from a state.
DefaultTransition<HMM.State,HMM.Symbol>[]	getTrans(HMM.State from, HMM.Symbol symbol) Returns all possible transitions for the given source state and symbol.
java.lang.Iterable<DefaultTransition<HMM.State,HMM.Symbol>>	getTrans2(HMM.State state)
java.lang.Iterable<DefaultTransition<HMM.State,HMM.Symbol>>	getTrans2(HMM.State state, HMM.Symbol symbol)
void	incrementTrainCount(DefaultTransition<HMM.State,HMM.Symbol> t, double count) Increments the training counts associated to a Transition.
void	incrementTrainCount(HMM.State state, double count) Increments the training counts associated to a final state.
void	initTrainCounts(double initCount) Initializes the training counts.
void	setName(java.lang.String name) Sets the name of the HMM.
java.lang.String	toString() Returns a string representation of the object.
java.lang.String	toXML() Returns a XML representation of the HMM

Methods inherited from class java.lang.Object

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

Field Detail

myFactory

public static final WFSA.Factory myFactory

Constructor Detail

HMM

public HMM(org.xml.sax.InputSource is)
    throws javax.xml.parsers.ParserConfigurationException,
           org.xml.sax.SAXException,
           java.io.IOException

Creates a HMM using an XML description found via an InputSource

Parameters:

is - the InputSource used to locate the XML description

Throws:

javax.xml.parsers.ParserConfigurationException

org.xml.sax.SAXException

java.io.IOException

HMM

public HMM(org.xml.sax.InputSource is,
           Alphabet<HMM.Symbol> alphabet)
    throws javax.xml.parsers.ParserConfigurationException,
           org.xml.sax.SAXException,
           java.io.IOException

Creates a HMM using a XML description found via an InputSource and using an existing Alphabet. The alphabet could grow.

Parameters:

is - the InputSource used to locate the XML description

alphabet - an existing Alphabet

Throws:

javax.xml.parsers.ParserConfigurationException

org.xml.sax.SAXException

java.io.IOException

Method Detail

setName

public void setName(java.lang.String name)

Sets the name of the HMM.

Parameters:

name - the name of this HMM

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

A string representation of the object

getName

public java.lang.String getName()

Description copied from interface: WFSA

Returns the name of the Model.

Specified by:

getName in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Returns:

The name of the Model

getSymbolByName

public HMM.Symbol getSymbolByName(java.lang.String name)

getAlphabet

public Alphabet<HMM.Symbol> getAlphabet()

Description copied from interface: WFSA

Returns the alphabet of the Model.

Specified by:

getAlphabet in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Returns:

The Alphabet

getFinProb

public double getFinProb(HMM.State state)

Description copied from interface: WFSA

Returns the probability of being final

Specified by:

getFinProb in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Returns:

The probability of being final

getIniState

public HMM.State getIniState()

Description copied from interface: WFSA

Returns the initial State

Specified by:

getIniState in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Returns:

The initial state

getTrans

public DefaultTransition<HMM.State,HMM.Symbol>[] getTrans(HMM.State from)

Description copied from interface: WFSA

Returns all possible transitions from a state.

Specified by:

getTrans in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Parameters:

from - The source State

Returns:

an array containing all possible transitions from a state. If there is no transition, and empty array must be returned.

getRandomTrans

public DefaultTransition<HMM.State,HMM.Symbol> getRandomTrans(HMM.State state)

Description copied from interface: WFSA

Returns a random transitions from a state

Specified by:

getRandomTrans in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Parameters:

state - The source State

Returns:

a random transition

getTrans2

public java.lang.Iterable<DefaultTransition<HMM.State,HMM.Symbol>> getTrans2(HMM.State state)
                                                                      throws java.lang.UnsupportedOperationException

Throws:

java.lang.UnsupportedOperationException

getTrans2

public java.lang.Iterable<DefaultTransition<HMM.State,HMM.Symbol>> getTrans2(HMM.State state,
                                                                             HMM.Symbol symbol)
                                                                      throws java.lang.UnsupportedOperationException

Throws:

java.lang.UnsupportedOperationException

getTrans

public DefaultTransition<HMM.State,HMM.Symbol>[] getTrans(HMM.State from,
                                                          HMM.Symbol symbol)

Description copied from interface: NdWFSA

Returns all possible transitions for the given source state and symbol. The array should be ordered in descending probability (the most probable transition is the first and the less probable is the last).

Specified by:

getTrans in interface NdWFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Parameters:

from - the source State

symbol - the observed symbol

Returns:

an array containing all possible transitions. If there is no transition, an empty array must be returned.

initTrainCounts

public void initTrainCounts(double initCount)

Description copied from interface: WFSA

Initializes the training counts. Al previous counts are cleared and initCount is used as initial posterior probability count of the WFSA (MAP training). This count must be distributed among all the internal parameters according to their prior probabilities.

Specified by:

initTrainCounts in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Parameters:

initCount - initial posterior probability count

incrementTrainCount

public void incrementTrainCount(HMM.State state,
                                double count)

Description copied from interface: WFSA

Increments the training counts associated to a final state. These counts are related to the final probability of a State.

Specified by:

incrementTrainCount in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Parameters:

state - the final Sate

count - the training count.

incrementTrainCount

public void incrementTrainCount(DefaultTransition<HMM.State,HMM.Symbol> t,
                                double count)

Description copied from interface: WFSA

Increments the training counts associated to a Transition. These counts are related to the probability of a Transition.

Specified by:

incrementTrainCount in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

Parameters:

t - the Transition

count - the training count.

dumpTrainCounts

public void dumpTrainCounts()

Dumps the trained data to the HMM. The Gopalakrishnan transformation

p'= (p * C + count) / Norma

is implemented using the value C=Max{(1-count)/prob,0} for each probability distribution. This constant ensures that the minimun probability (prior to normalization) will be 1.

Specified by:

dumpTrainCounts in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>

toXML

public java.lang.String toXML()

Returns a XML representation of the HMM

Specified by:

toXML in interface WFSA<HMM.State,HMM.Symbol,DefaultTransition<HMM.State,HMM.Symbol>>