Node (sphinx4-core 5prealpha-SNAPSHOT API)

java.lang.Object
- edu.cmu.sphinx.result.Node

```
public class Node
extends java.lang.Object
```
A node is part of Lattices, representing the theory that a word was spoken over a given period of time. A node also has a set of entering and leaving edges, connecting it to other nodes. One can get and set the beginning and end frames of the word via the getBeginTime and getEndTime methods. When setting these times, the beginning time must be earlier or equal to the end time, otherwise an error will be thrown.

The posterior probability of any word in a word lattice is the probability that the node representing that word occurs on any path through the lattice. It is usually computed as the ratio of the total likelihood scores of all paths through the lattice that pass through the node, to the total likelihood score of all paths through the lattice. Path scores are usually computed using the acoustic likelihoods of the nodes, although language scores can also be incorporated. The posterior probabilities of an entire lattice is usually computed efficiently using the Forward-Backward Algorithm. Refer to the computeNodePosteriors method in the Lattice class for details.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`Node(java.lang.String id, Word word, long beginTime, long endTime)` Create a new Node with given ID.
`protected`	`Node(Word word, long beginTime, long endTime)` Create a new Node

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`addEnteringEdge(Edge e)` Add an Edge from this Node
`protected void`	`addLeavingEdge(Edge e)` Add an Edge to this Node
`protected void`	`cacheDescendants()`
`protected void`	`cacheDescendantsHelper(Node n)`
`void`	`dumpDot(java.io.FileWriter f)` Internal routine when dumping Lattices as Graphviz files
`boolean`	`equals(java.lang.Object obj)` Assumes ids are unique node identifiers
`Edge`	`findEquivalentLeavingEdge(Edge edge)` Returns a leaving edge that is equivalent to the given edge.
`double`	`getBackwardScore()` Returns the backward score, which is calculated during the computation of the posterior score for this node.
`long`	`getBeginTime()` Get the frame number when the word began
`Node`	`getBestPredecessor()` Returns the best predecessor for this node.
`java.util.List<Node>`	`getChildNodes()` Get the nodes at the other ends of outgoing edges of this node.
`java.util.Collection<Edge>`	`getCopyOfEnteringEdges()` Returns a copy of the Edges to this Node, so that the underlying data structure will not be modified.
`java.util.Collection<Edge>`	`getCopyOfLeavingEdges()` Returns a copy of the Edges from this Node, so that the underlying data structure will not be modified.
`Edge`	`getEdgeFromNode(Node n)` given a node find the edge from that node
`Edge`	`getEdgeToNode(Node n)` given a node find the edge to that node
`long`	`getEndTime()` Get the frame number when the word ends
`java.util.Collection<Edge>`	`getEnteringEdges()` Get the Edges to this Node
`double`	`getForwardScore()` Returns the forward score, which is calculated during the computation of the posterior score for this node.
`java.lang.String`	`getId()` Get the ID associated with this Node
`java.util.Collection<Edge>`	`getLeavingEdges()` Get the Edges from this Node
`protected static java.lang.String`	`getNextNodeId()` Get a unique ID for a new Node.
`double`	`getPosterior()` Returns the posterior probability of this node.
`TimeFrame`	`getTimeFrame()` Returns TimeFrame of the Node
`double`	`getViterbiScore()` Returns the Viterbi score for this node.
`Word`	`getWord()` Get the word associated with this Node
`boolean`	`hasAncestralRelationship(Node node)` Check whether this node has an ancestral relationship with another node (i.e. either this node is an ancestor of the other node, or vice versa)
`protected boolean`	`hasEdgeFromNode(Node n)` Test is a Node has an Edge from a Node
`protected boolean`	`hasEdgeToNode(Node n)` Test if a node has an Edge to a Node
`protected boolean`	`hasEquivalentEnteringEdges(Node n)` Test if a Node has all Edges from the same Nodes and another Node.
`boolean`	`hasEquivalentLeavingEdges(Node n)` Test if a Node has all Edges to the same Nodes and another Node.
`int`	`hashCode()`
`protected boolean`	`isAncestorHelper(java.util.List<Node> children, Node node, java.util.Set<Node> seenNodes)`
`boolean`	`isAncestorOf(Node node)` Check whether this node is an ancestor of another node.
`boolean`	`isEquivalent(Node other)` Returns true if the given node is equivalent to this node.
`protected void`	`removeEnteringEdge(Edge e)` Remove an Edge from this Node
`void`	`removeLeavingEdge(Edge e)` Remove an Edge to this Node
`void`	`setBackwardScore(double backwardScore)` Sets the backward score for this node.
`void`	`setBeginTime(long beginTime)` Sets the frame number when the word began.
`void`	`setBestPredecessor(Node bestPredecessor)` Sets the best predecessor of this node.
`void`	`setEndTime(long endTime)` Sets the frame number when the words ended.
`void`	`setForwardScore(double forwardScore)` Sets the backward score for this node.
`void`	`setPosterior(double posterior)` Sets the posterior probability of this node.
`void`	`setViterbiScore(double viterbiScore)` Sets the Viterbi score for this node.
`java.lang.String`	`toString()` Returns a description of this Node that contains the word, the start time, and the end time.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Node
```
protected Node(Word word,
               long beginTime,
               long endTime)
```
    Create a new Node
    
    Parameters:
    
    word - the word of this node
    
    beginTime - the start time of the word
    
    endTime - the end time of the word
  - Node
```
protected Node(java.lang.String id,
               Word word,
               long beginTime,
               long endTime)
```
    Create a new Node with given ID. Used when creating a Lattice from a .LAT file
    
    Parameters:
    
    id - id of the node
    
    word - word
    
    beginTime - begin time
    
    endTime - end time
- Method Detail
  - getNextNodeId
```
protected static java.lang.String getNextNodeId()
```
    Get a unique ID for a new Node. Used when creating a Lattice from a .LAT file
    
    Returns:
    
    the unique ID for a new node
  - hasEdgeToNode
```
protected boolean hasEdgeToNode(Node n)
```
    Test if a node has an Edge to a Node
    
    Parameters:
    
    n - node to check
    
    Returns:
    
    unique Node ID
  - getEdgeToNode
```
public Edge getEdgeToNode(Node n)
```
    given a node find the edge to that node
    
    Parameters:
    
    n - the node of interest
    
    Returns:
    
    the edge to that node or null if no edge could be found.
  - hasEdgeFromNode
```
protected boolean hasEdgeFromNode(Node n)
```
    Test is a Node has an Edge from a Node
    
    Parameters:
    
    n - node to check
    
    Returns:
    
    true if this node has an Edge from n
  - getEdgeFromNode
```
public Edge getEdgeFromNode(Node n)
```
    given a node find the edge from that node
    
    Parameters:
    
    n - the node of interest
    
    Returns:
    
    the edge from that node or null if no edge could be found.
  - hasEquivalentEnteringEdges
```
protected boolean hasEquivalentEnteringEdges(Node n)
```
    Test if a Node has all Edges from the same Nodes and another Node.
    
    Parameters:
    
    n - node to check
    
    Returns:
    
    true if this Node has Edges from the same Nodes as n
  - hasEquivalentLeavingEdges
```
public boolean hasEquivalentLeavingEdges(Node n)
```
    Test if a Node has all Edges to the same Nodes and another Node.
    
    Parameters:
    
    n - the node of interest
    
    Returns:
    
    true if this Node has all Edges to the sames Nodes as n
  - getEnteringEdges
```
public java.util.Collection<Edge> getEnteringEdges()
```
    Get the Edges to this Node
    
    Returns:
    
    Edges to this Node
  - getLeavingEdges
```
public java.util.Collection<Edge> getLeavingEdges()
```
    Get the Edges from this Node
    
    Returns:
    
    Edges from this Node
  - getCopyOfEnteringEdges
```
public java.util.Collection<Edge> getCopyOfEnteringEdges()
```
    Returns a copy of the Edges to this Node, so that the underlying data structure will not be modified.
    
    Returns:
    
    a copy of the edges to this node
  - getCopyOfLeavingEdges
```
public java.util.Collection<Edge> getCopyOfLeavingEdges()
```
    Returns a copy of the Edges from this Node, so that the underlying data structure will not be modified.
    
    Returns:
    
    a copy of the edges from this node
  - addEnteringEdge
```
protected void addEnteringEdge(Edge e)
```
    Add an Edge from this Node
    
    Parameters:
    
    e - edge to add
  - addLeavingEdge
```
protected void addLeavingEdge(Edge e)
```
    Add an Edge to this Node
    
    Parameters:
    
    e - edge to add
  - removeEnteringEdge
```
protected void removeEnteringEdge(Edge e)
```
    Remove an Edge from this Node
    
    Parameters:
    
    e - edge to remove
  - removeLeavingEdge
```
public void removeLeavingEdge(Edge e)
```
    Remove an Edge to this Node
    
    Parameters:
    
    e - the edge to remove
  - getId
```
public java.lang.String getId()
```
    Get the ID associated with this Node
    
    Returns:
    
    the ID
  - getWord
```
public Word getWord()
```
    Get the word associated with this Node
    
    Returns:
    
    the word
  - getBeginTime
```
public long getBeginTime()
```
    Get the frame number when the word began
    
    Returns:
    
    the begin frame number, or -1 if the frame number is unknown
  - setBeginTime
```
public void setBeginTime(long beginTime)
```
    Sets the frame number when the word began. The begin time must be not be later than the time returned by the getEndTime() method, otherwise an error will be thrown.
    
    Parameters:
    
    beginTime - the frame number when the word began
  - getEndTime
```
public long getEndTime()
```
    Get the frame number when the word ends
    
    Returns:
    
    the end time, or -1 if the frame number if is unknown
  - setEndTime
```
public void setEndTime(long endTime)
```
    Sets the frame number when the words ended. The end time must not be earlier than the time returned by the getEndTime() method, otherwise an error will be thrown.
    
    Parameters:
    
    endTime - the frame number when the word ended
  - getTimeFrame
```
public TimeFrame getTimeFrame()
```
    Returns TimeFrame of the Node
    
    Returns:
    
    TimeFrame
  - toString
```
public java.lang.String toString()
```
    Returns a description of this Node that contains the word, the start time, and the end time.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a description of this Node
  - dumpDot
```
public void dumpDot(java.io.FileWriter f)
             throws java.io.IOException
```
    Internal routine when dumping Lattices as Graphviz files
    
    Parameters:
    
    f - file writer to store
    
    Throws:
    
    java.io.IOException - if error occurred
  - getBackwardScore
```
public double getBackwardScore()
```
    Returns the backward score, which is calculated during the computation of the posterior score for this node.
    
    Returns:
    
    Returns the backwardScore.
  - setBackwardScore
```
public void setBackwardScore(double backwardScore)
```
    Sets the backward score for this node.
    
    Parameters:
    
    backwardScore - The backwardScore to set.
  - getForwardScore
```
public double getForwardScore()
```
    Returns the forward score, which is calculated during the computation of the posterior score for this node.
    
    Returns:
    
    Returns the forwardScore.
  - setForwardScore
```
public void setForwardScore(double forwardScore)
```
    Sets the backward score for this node.
    
    Parameters:
    
    forwardScore - The forwardScore to set.
  - getPosterior
```
public double getPosterior()
```
    Returns the posterior probability of this node. Refer to the javadocs for this class for a description of posterior probabilities.
    
    Returns:
    
    Returns the posterior probability of this node.
  - setPosterior
```
public void setPosterior(double posterior)
```
    Sets the posterior probability of this node. Refer to the javadocs for this class for a description of posterior probabilities.
    
    Parameters:
    
    posterior - The node posterior probability to set.
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
    
    See Also:
    
    Object.hashCode()
  - equals
```
public boolean equals(java.lang.Object obj)
```
    Assumes ids are unique node identifiers
    
    Overrides:
    
    equals in class java.lang.Object
    
    See Also:
    
    Object.equals(java.lang.Object)
  - getChildNodes
```
public java.util.List<Node> getChildNodes()
```
    Get the nodes at the other ends of outgoing edges of this node.
    
    Returns:
    
    a list of child nodes
  - cacheDescendants
```
protected void cacheDescendants()
```
  - cacheDescendantsHelper
```
protected void cacheDescendantsHelper(Node n)
```
  - isAncestorHelper
```
protected boolean isAncestorHelper(java.util.List<Node> children,
                                   Node node,
                                   java.util.Set<Node> seenNodes)
```
  - isAncestorOf
```
public boolean isAncestorOf(Node node)
```
    Check whether this node is an ancestor of another node.
    
    Parameters:
    
    node - the Node to check
    
    Returns:
    
    whether this node is an ancestor of the passed in node.
  - hasAncestralRelationship
```
public boolean hasAncestralRelationship(Node node)
```
    Check whether this node has an ancestral relationship with another node (i.e. either this node is an ancestor of the other node, or vice versa)
    
    Parameters:
    
    node - the Node to check for a relationship
    
    Returns:
    
    whether a relationship exists
  - isEquivalent
```
public boolean isEquivalent(Node other)
```
    Returns true if the given node is equivalent to this node. Two nodes are equivalent only if they have the same word, the same number of entering and leaving edges, and that their begin and end times are the same.
    
    Parameters:
    
    other - the Node we're comparing to
    
    Returns:
    
    true if the Node is equivalent; false otherwise
  - findEquivalentLeavingEdge
```
public Edge findEquivalentLeavingEdge(Edge edge)
```
    Returns a leaving edge that is equivalent to the given edge. Two edges are eqivalent if Edge.isEquivalent() returns true.
    
    Parameters:
    
    edge - the Edge to compare the leaving edges of this node against
    
    Returns:
    
    an equivalent edge, if any; or null if no equivalent edge
  - getBestPredecessor
```
public Node getBestPredecessor()
```
    Returns the best predecessor for this node.
    
    Returns:
    
    Returns the bestPredecessor.
  - setBestPredecessor
```
public void setBestPredecessor(Node bestPredecessor)
```
    Sets the best predecessor of this node.
    
    Parameters:
    
    bestPredecessor - The bestPredecessor to set.
  - getViterbiScore
```
public double getViterbiScore()
```
    Returns the Viterbi score for this node. The Viterbi score is usually computed during the speech recognition process.
    
    Returns:
    
    Returns the viterbiScore.
  - setViterbiScore
```
public void setViterbiScore(double viterbiScore)
```
    Sets the Viterbi score for this node. The Viterbi score is usually computed during the speech recognition process.
    
    Parameters:
    
    viterbiScore - The viterbiScore to set.

Class Node

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Node

Node

Method Detail

getNextNodeId

hasEdgeToNode

getEdgeToNode

hasEdgeFromNode

getEdgeFromNode

hasEquivalentEnteringEdges

hasEquivalentLeavingEdges

getEnteringEdges

getLeavingEdges

getCopyOfEnteringEdges

getCopyOfLeavingEdges

addEnteringEdge

addLeavingEdge

removeEnteringEdge

removeLeavingEdge

getId

getWord

getBeginTime

setBeginTime

getEndTime

setEndTime

getTimeFrame

toString

dumpDot

getBackwardScore

setBackwardScore

getForwardScore

setForwardScore

getPosterior

setPosterior

hashCode

equals

getChildNodes

cacheDescendants

cacheDescendantsHelper

isAncestorHelper

isAncestorOf

hasAncestralRelationship

isEquivalent

findEquivalentLeavingEdge

getBestPredecessor

setBestPredecessor

getViterbiScore

setViterbiScore