joshua.decoder.chart_parser.DotChart Class Reference

Collaboration diagram for joshua.decoder.chart_parser.DotChart:

List of all members.

Classes
class	DotCell
class	DotNode
Public Member Functions
DotCell	getDotCell (int i, int j)
	DotChart (Lattice< Integer > input, Grammar grammar, Chart chart)
Package Functions
void	seed ()
void	expandDotCell (int i, int j)
void	startDotItems (int i, int j)
Private Member Functions
void	extendDotItemsWithProvedItems (int i, int k, int j, boolean startDotItems)
void	addDotItem (Trie tnode, int i, int j, List< SuperNode > antSuperNodesIn, SuperNode curSuperNode, SourcePath srcPath)
Private Attributes
DotCell[][]	dotcells
Chart	dotChart
Grammar	pGrammar
final int	sentLen
final Lattice< Integer >	input
Static Private Attributes
static final Logger	logger = Logger.getLogger(DotChart.class.getName())

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Detailed Description

The DotChart handles the building of the -LM forest. The set of (Dot)Items over a span represent the rules that have been completely applied through the implicit binarization. These DotItems are available to be incorporated into the main chart after the LM score has been applied (assuming they pass pruning).

DotItem represent (possibly partial) application of synchronous rules that have been implicitly binarized. As spans are considered, the next symbol in the rule's source right-hand side is matched against proved items (items in the +LM chart, Chart.java) or input symbols. Once the rule is complete, it is entered into the DotChart.

Author:

Zhifei Li, zhife.nosp@m.i.wo.nosp@m.rk@gm.nosp@m.ail..nosp@m.com

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Constructor & Destructor Documentation

joshua.decoder.chart_parser.DotChart.DotChart	(	Lattice< Integer >	input,
		Grammar	grammar,
		Chart	chart
	)

Constructs a new dot chart from a specified input lattice, a translation grammar, and a parse chart.

Parameters:

input	A lattice which represents an input sentence.
grammar	A translation grammar.
chart	A CKY+ style chart in which completed span entries are stored.

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Member Function Documentation

void joshua.decoder.chart_parser.DotChart.addDotItem	(	Trie	tnode,
		int	i,
		int	j,
		List< SuperNode >	antSuperNodesIn,
		SuperNode	curSuperNode,
		SourcePath	srcPath
	)		[private]

Creates a dot item and adds it into the cell(i,j) of this dot chart.

Parameters:

tnode
i
j
ant_s_items_in
curSuperNode

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void joshua.decoder.chart_parser.DotChart.expandDotCell	(	int	i,
		int	j
	)		[package]

two kinds of symbols in the foreign side: (1) non-terminal (e.g., X or NP); (2) CN-side terminal therefore, two ways to extend the dot postion.

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void joshua.decoder.chart_parser.DotChart.extendDotItemsWithProvedItems	(	int	i,
		int	k,
		int	j,
		boolean	startDotItems
	)		[private]

Attempt to combine an item in the dot chart with an item in the chart to create a new item in the dot chart.

In other words, this method looks for (proved) theorems or axioms in the completed chart that may apply and extend the dot position.

Parameters:

i	Start index of a dot chart item
k	End index of a dot chart item; start index of a completed chart item
j	End index of a completed chart item
startDotItems

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DotCell joshua.decoder.chart_parser.DotChart.getDotCell	(	int	i,
		int	j
	)

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void joshua.decoder.chart_parser.DotChart.seed

(

)

[package]

Constructs a new dot chart from a specified input sentence, a translation grammar, and a parse chart.

Parameters:

input	An array of integers which represents an input sentence.
grammar	A translation grammar.
chart	A CKY+ style chart in which completed span entries are stored. add intial dot items: dot-items pointer to the root of the grammar trie.

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void joshua.decoder.chart_parser.DotChart.startDotItems	(	int	i,
		int	j
	)		[package]

note: (i,j) is a non-terminal, this cannot be a cn-side terminal, which have been handled in case2 of dotchart.expand_cell add dotitems that start with the complete super-items in cell(i,j)

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Member Data Documentation

DotCell [][] joshua.decoder.chart_parser.DotChart.dotcells [private]

Two-dimensional chart of cells. Some cells might be null. This could definitely be represented more efficiently, especially since access is already mitigated through an accessor function.

Chart joshua.decoder.chart_parser.DotChart.dotChart [private]

CKY+ style parse chart in which completed span entries are stored.

final Lattice<Integer> joshua.decoder.chart_parser.DotChart.input [private]

Represents the input sentence being translated.

final Logger joshua.decoder.chart_parser.DotChart.logger = Logger.getLogger(DotChart.class.getName()) [static, private]

Grammar joshua.decoder.chart_parser.DotChart.pGrammar [private]

Translation grammar which contains the translation rules.

final int joshua.decoder.chart_parser.DotChart.sentLen [private]

Length of input sentence.