edu.cmu.sphinx.linguist.language.classes

Class ClassBasedLanguageModel

java.lang.Object

edu.cmu.sphinx.linguist.language.classes.ClassBasedLanguageModel

All Implemented Interfaces:

LanguageModel, Configurable

public class ClassBasedLanguageModel
extends java.lang.Object
implements LanguageModel

An LM that computes a probability of a word sequence by converting words to classes and asking the class-based probability from a delegate LM.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	PROP_CLASS_LANGUAGE_MODEL The property that defines the classLanguageModel component.
static java.lang.String	PROP_CLASS_MAP The property that defines the classMap component.

Fields inherited from interface edu.cmu.sphinx.linguist.language.ngram.LanguageModel

PROP_DICTIONARY, PROP_LOCATION, PROP_MAX_DEPTH, PROP_UNIGRAM_WEIGHT

Constructor Summary

Constructors

Constructor and Description
ClassBasedLanguageModel()
ClassBasedLanguageModel(ClassMap classMap, LanguageModel classLM)

Method Summary

Modifier and Type	Method and Description
void	allocate() Create the language model
void	deallocate() Deallocate resources allocated to this language model
int	getMaxDepth() Returns the maximum depth of the language model
float	getProbability(WordSequence wordSequence) Actual implementation of the class-based LM: P=P(W|C1)*P(C1|C2,C3..)
float	getSmear(WordSequence wordSequence) Gets the smear term for the given wordSequence
java.util.Set<java.lang.String>	getVocabulary() Returns the set of words in the language model.
void	newProperties(PropertySheet ps) This method is called when this configurable component needs to be reconfigured.
void	onUtteranceEnd() Called on utterance end to clear cache if needed

Methods inherited from class java.lang.Object

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

Field Detail

PROP_CLASS_LANGUAGE_MODEL

@S4Component(type=LanguageModel.class)
public static final java.lang.String PROP_CLASS_LANGUAGE_MODEL

The property that defines the classLanguageModel component.

See Also:

Constant Field Values

PROP_CLASS_MAP

@S4Component(type=ClassMap.class)
public static final java.lang.String PROP_CLASS_MAP

The property that defines the classMap component.

See Also:

Constant Field Values

Constructor Detail

ClassBasedLanguageModel

public ClassBasedLanguageModel(ClassMap classMap,
                               LanguageModel classLM)

ClassBasedLanguageModel

public ClassBasedLanguageModel()

Method Detail

newProperties

public void newProperties(PropertySheet ps)
                   throws PropertyException

Description copied from interface: Configurable

This method is called when this configurable component needs to be reconfigured.

Specified by:

newProperties in interface Configurable

Parameters:

ps - a property sheet holding the new data

Throws:

PropertyException - if there is a problem with the properties.

allocate

public void allocate()
              throws java.io.IOException

Description copied from interface: LanguageModel

Create the language model

Specified by:

allocate in interface LanguageModel

Throws:

java.io.IOException - if error occurrs

deallocate

public void deallocate()
                throws java.io.IOException

Description copied from interface: LanguageModel

Deallocate resources allocated to this language model

Specified by:

deallocate in interface LanguageModel

Throws:

java.io.IOException - if error occurrs

getProbability

public float getProbability(WordSequence wordSequence)

Actual implementation of the class-based LM: P=P(W|C1)*P(C1|C2,C3..)

Specified by:

getProbability in interface LanguageModel

Parameters:

wordSequence - the wordSequence

Returns:

the probability of the word sequence in log base

See Also:

LanguageModel.getProbability( edu.cmu.sphinx.linguist.WordSequence)

getSmear

public float getSmear(WordSequence wordSequence)

Gets the smear term for the given wordSequence

Specified by:

getSmear in interface LanguageModel

Parameters:

wordSequence - the word sequence

Returns:

the smear term associated with this word sequence

getVocabulary

public java.util.Set<java.lang.String> getVocabulary()

Description copied from interface: LanguageModel

Returns the set of words in the language model. The set is unmodifiable.

Specified by:

getVocabulary in interface LanguageModel

Returns:

the unmodifiable set of words

getMaxDepth

public int getMaxDepth()

Returns the maximum depth of the language model

Specified by:

getMaxDepth in interface LanguageModel

Returns:

the maximum depth of the language mdoel

onUtteranceEnd

public void onUtteranceEnd()

Description copied from interface: LanguageModel

Called on utterance end to clear cache if needed

Specified by:

onUtteranceEnd in interface LanguageModel