edu.cmu.sphinx.linguist.flat

Class FlatLinguist.GState

java.lang.Object

edu.cmu.sphinx.linguist.flat.FlatLinguist.GState

Enclosing class:

FlatLinguist

protected class FlatLinguist.GState
extends java.lang.Object

This is a nested class that is used to manage the construction of the states in a grammar node. There is one GState created for each grammar node. The GState is used to collect the entry and exit points for the grammar node and for connecting up the grammar nodes to each other.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	GState(GrammarNode node) Creates a GState for a grammar node

Method Summary

Modifier and Type	Method and Description
protected void	attachState(SentenceHMMState prevState, SentenceHMMState nextState, float logLanguageProbablity, float logInsertionProbablity) Attaches one SentenceHMMState as a child to another, the transition has the given probability
void	collectContexts() Collects the right contexts for this node and pushes this nodes ending context into the next next set of nodes.
void	connect() Connect up all of the GStates.
void	expand() Expands each GState into the sentence HMM States
protected SentenceHMMState	expandUnit(UnitState unit) Expands the unit into a set of HMMStates.
SentenceHMMState	getEntryPoint() Gets the context-free entry point to this state
protected int	getLeftContextSize() Returns the size of the left context.
protected int	getRightContextSize() Returns the size of the right context.
java.util.Collection<SearchState>	getStates() Returns all of the states maintained by this gstate
java.lang.String	toString() Returns the string representation of the object

Methods inherited from class java.lang.Object

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

Constructor Detail

GState

protected GState(GrammarNode node)

Creates a GState for a grammar node

Parameters:

node - the grammar node

Method Detail

getEntryPoint

public SentenceHMMState getEntryPoint()

Gets the context-free entry point to this state

Returns:

the entry point to the state

collectContexts

public void collectContexts()

Collects the right contexts for this node and pushes this nodes ending context into the next next set of nodes.

expand

public void expand()

Expands each GState into the sentence HMM States

getLeftContextSize

protected int getLeftContextSize()

Returns the size of the left context.

Returns:

the size of the left context

getRightContextSize

protected int getRightContextSize()

Returns the size of the right context.

Returns:

the size of the right context

expandUnit

protected SentenceHMMState expandUnit(UnitState unit)

Expands the unit into a set of HMMStates. If the unit is a silence unit add an optional loopback to the tail.

Parameters:

unit - the unit to expand

Returns:

the head of the hmm tree

connect

public void connect()

Connect up all of the GStates. Each state now has a table of exit points. These exit points represent tail states for the node. Each of these tail states is tagged with a ContextPair, that indicates what the left context is (the exiting context) and the right context (the entering context) for the transition. To connect up a state, the connect does the following: 1) Iterate through all of the grammar successors for this state 2) Get the 'entry points' for the successor that match the exit points. 3) Hook them up.

Note that for a task with 1000 words this will involve checking on the order of 35,000,000 connections and making about 2,000,000 connections

attachState

protected void attachState(SentenceHMMState prevState,
                           SentenceHMMState nextState,
                           float logLanguageProbablity,
                           float logInsertionProbablity)

Attaches one SentenceHMMState as a child to another, the transition has the given probability

Parameters:

prevState - the parent state

nextState - the child state

logLanguageProbablity - the language probability of transition in the LogMath log domain

logInsertionProbablity - insertion probability of transition in the LogMath log domain

getStates

public java.util.Collection<SearchState> getStates()

Returns all of the states maintained by this gstate

Returns:

the set of all states

toString

public java.lang.String toString()

Returns the string representation of the object

Overrides:

toString in class java.lang.Object

Returns:

the string representation of the object