edu.cmu.sphinx.linguist.language.ngram
Class SimpleNGramModel

java.lang.Object
  edu.cmu.sphinx.linguist.language.ngram.SimpleNGramModel

All Implemented Interfaces:

LanguageModel, Configurable

public class SimpleNGramModel
extends java.lang.Object
implements LanguageModel

An ascii ARPA language model loader. This loader makes no attempt to optimize storage, so it can only load very small language models

Note that all probabilites in the grammar are stored in LogMath log base format. Language Probabilties in the language model file are stored in log 10 base.

Field Summary

static java.lang.String

PROP_LOG_MATH Sphinx property that defines the logMath component.

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

PROP_DICTIONARY, PROP_FORMAT, PROP_FORMAT_DEFAULT, PROP_LOCATION, PROP_LOCATION_DEFAULT, PROP_MAX_DEPTH, PROP_MAX_DEPTH_DEFAULT, PROP_UNIGRAM_WEIGHT, PROP_UNIGRAM_WEIGHT_DEFAULT

Constructor Summary

SimpleNGramModel()

Method Summary

void	allocate() Create the language model
void	deallocate() Deallocate resources allocated to this language model
void	dump() Dumps the language model
float	getBackoff(WordSequence wordSequence) Returns the backoff probability for the give sequence of words
java.util.logging.Logger	getLogger() Used for reporting errors and warnings during loading
int	getMaxDepth() Returns the maximum depth of the language model
java.lang.String	getName()
float	getProbability(WordSequence wordSequence) Gets the ngram probability of the word sequence represented by the word list
float	getSmear(WordSequence wordSequence) Gets the smear term for the given wordSequence
java.util.Set	getVocabulary() Returns the set of words in the lanaguage model.
void	newProperties(PropertySheet ps) This method is called when this configurable component needs to be reconfigured.
void	start() Called before a recognition
void	stop() Called after a recognition

Methods inherited from class java.lang.Object

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

Field Detail

PROP_LOG_MATH

@S4Component(type=LogMath.class)
public static final java.lang.String PROP_LOG_MATH

Sphinx property that defines the logMath component.

See Also:

Constant Field Values

Constructor Detail

SimpleNGramModel

public SimpleNGramModel()

Method Detail

getLogger

public java.util.logging.Logger getLogger()

Description copied from interface: LanguageModel

Used for reporting errors and warnings during loading

Specified by:

getLogger in interface LanguageModel

Returns:

the logger used by the LanguageModel

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

deallocate

public void deallocate()

Description copied from interface: LanguageModel

Deallocate resources allocated to this language model

Specified by:

deallocate in interface LanguageModel

getName

public java.lang.String getName()

start

public void start()

Called before a recognition

Specified by:

start in interface LanguageModel

stop

public void stop()

Called after a recognition

Specified by:

stop in interface LanguageModel

getProbability

public float getProbability(WordSequence wordSequence)

Gets the ngram probability of the word sequence represented by the word list

Specified by:

getProbability in interface LanguageModel

Parameters:

wordSequence - the word sequence

Returns:

the probability of the word sequence. Probability is in logMath log base

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

getBackoff

public float getBackoff(WordSequence wordSequence)

Returns the backoff probability for the give sequence of words

Parameters:

wordSequence - the sequence of words

Returns:

the backoff probability in LogMath log base

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

getVocabulary

public java.util.Set getVocabulary()

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

Specified by:

getVocabulary in interface LanguageModel

Returns:

the unmodifiable set of words

dump

public void dump()

Dumps the language model