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Stanford Parser processes raw text in English, Chinese, German, Arabic, and French, and extracts constituency parse trees.
// Stanford Parser -- a probabilistic lexicalized NL CFG parser
// Copyright (c) 2002-2006 The Board of Trustees of
// The Leland Stanford Junior University. All Rights Reserved.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// For more information, bug reports, fixes, contact:
// Christopher Manning
// Dept of Computer Science, Gates 1A
// Stanford CA 94305-9010
// USA
// [email protected]
// http://nlp.stanford.edu/downloads/lex-parser.shtml
package edu.stanford.nlp.parser.lexparser;
import java.util.*;
import edu.stanford.nlp.util.Index;
import edu.stanford.nlp.util.Timing;
import edu.stanford.nlp.util.StringUtils;
import edu.stanford.nlp.util.ScoredObject;
import edu.stanford.nlp.trees.TreeFactory;
import edu.stanford.nlp.trees.TreebankLanguagePack;
import edu.stanford.nlp.trees.Tree;
import edu.stanford.nlp.trees.LabeledScoredTreeFactory;
import edu.stanford.nlp.ling.CategoryWordTag;
import edu.stanford.nlp.ling.HasContext;
import edu.stanford.nlp.ling.HasTag;
import edu.stanford.nlp.ling.HasWord;
import edu.stanford.nlp.ling.Label;
import edu.stanford.nlp.ling.Word;
import edu.stanford.nlp.parser.KBestViterbiParser;
import edu.stanford.nlp.util.RuntimeInterruptedException;
/**
* An exhaustive O(n4t2) time and O(n2t)
* space dependency parser.
* This follows the general
* picture of the Eisner and Satta dependency parsing papers, but without the
* tricks in defining items that they use to get an O(n3)
* dependency parser. The parser is as described in:
*
* Dan Klein and Christopher D. Manning. 2003. Fast Exact Inference with a
* Factored Model for Natural Language Parsing. In Suzanna Becker, Sebastian
* Thrun, and Klaus Obermayer (eds), Advances in Neural Information Processing
* Systems 15 (NIPS 2002). Cambridge, MA: MIT Press, pp. 3-10.
* http://nlp.stanford.edu/pubs/lex-parser.pdf
*
*
* @author Dan Klein
*/
public class ExhaustiveDependencyParser implements Scorer, KBestViterbiParser {
private static final boolean DEBUG = false;
private static final boolean DEBUG_MORE = false;
private final Index tagIndex;
private final Index wordIndex;
private TreeFactory tf;
private DependencyGrammar dg;
private Lexicon lex;
private Options op;
private TreebankLanguagePack tlp;
private List sentence;
private int[] words;
/**
* Max log inner probability score.
*
* Indices:
* 1. headPos - index of head word (one side of subtree)
* 2. headTag - which tag assigned
* 3. cornerPosition - other end of span, i.e. "corner" of right triangle
*/
private float[][][] iScoreH; // headPos, headTag, cornerPosition (non-head)
/**
* Max log outer probability score. Same indices as iScoreH.
*/
private float[][][] oScoreH; // headPos, headTag, cornerPosition (non-head)
/**
* Total log inner probability score. Same indices as iScoreH. Designed for
* producing summed total probabilities. Unfinished.
*/
private float[][][] iScoreHSum;
/** If true, compute iScoreHSum */
private static final boolean doiScoreHSum = false;
private int[][] rawDistance;
int[][] binDistance; // reused in other class, so can't be private
float[][][][][] headScore;
float[][][] headStop; // headPos, headTag, split
private boolean[][][] oPossibleByL;
private boolean[][][] oPossibleByR;
private boolean[][][] iPossibleByL;
private boolean[][][] iPossibleByR;
private int arraySize = 0;
private int myMaxLength = -0xDEADBEEF;
float oScore(int start, int end, int head, int tag) {
return oScoreH[head][dg.tagBin(tag)][start] + oScoreH[head][dg.tagBin(tag)][end];
}
/**
* Probability of *most likely* parse having word (at head) with given POS
* tag as marker on tree over start (inclusive) ... end (exclusive). Found
* by summing (product done in log space) the log probabilities in the two
* half-triangles. The indices of iScoreH are: (1) head word index,
* (2) head tag assigned, and (3) other corner that ends span.
*/
float iScore(int start, int end, int head, int tag) {
return iScoreH[head][dg.tagBin(tag)][start] + iScoreH[head][dg.tagBin(tag)][end];
}
/**
* Total probability of all parses having word (at head) with given POS tag
* as marker on tree over start (inclusive) .. end (exclusive).
*
* TODO: CURRENTLY UNTESTED!
*/
float iScoreTotal(int start, int end, int head, int tag) {
if (!doiScoreHSum) {
throw new RuntimeException("Summed inner scores not computed");
}
// log scores: so + => * and exploiting independence of left and right choices
return iScoreHSum[head][dg.tagBin(tag)][start] + iScoreHSum[head][dg.tagBin(tag)][end];
}
public double oScore(Edge edge) {
return oScore(edge.start, edge.end, edge.head, edge.tag);
}
public double iScore(Edge edge) {
return iScore(edge.start, edge.end, edge.head, edge.tag);
}
public boolean oPossible(Hook hook) {
return (hook.isPreHook() ? oPossibleByR[hook.end][hook.head][dg.tagBin(hook.tag)] : oPossibleByL[hook.start][hook.head][dg.tagBin(hook.tag)]);
}
public boolean iPossible(Hook hook) {
return (hook.isPreHook() ? iPossibleByR[hook.start][hook.head][dg.tagBin(hook.tag)] : iPossibleByL[hook.end][hook.head][dg.tagBin(hook.tag)]);
}
public boolean parse(List sentence) {
if (op.testOptions.verbose) {
Timing.tick("Starting dependency parse.");
}
this.sentence = sentence;
int length = sentence.size();
if (length > arraySize) {
if (length > op.testOptions.maxLength + 1 || length >= myMaxLength) {
throw new OutOfMemoryError("Refusal to create such large arrays.");
} else {
try {
createArrays(length + 1);
} catch (OutOfMemoryError e) {
myMaxLength = length;
if (arraySize > 0) {
try {
createArrays(arraySize);
} catch (OutOfMemoryError e2) {
throw new RuntimeException("CANNOT EVEN CREATE ARRAYS OF ORIGINAL SIZE!!! " + arraySize);
}
}
throw e;
}
arraySize = length + 1;
if (op.testOptions.verbose) {
System.err.println("Created dparser arrays of size " + arraySize);
}
}
}
if (op.testOptions.verbose) {
System.err.print("Initializing...");
}
// map to words
words = new int[length];
int numTags = dg.numTagBins();//tagIndex.size();
//System.out.println("\nNumTags: "+numTags);
//System.out.println(tagIndex);
boolean[][] hasTag = new boolean[length][numTags];
for (int i = 0; i < length; i++) {
//if (wordIndex.contains(sentence.get(i).toString()))
words[i] = wordIndex.addToIndex(sentence.get(i).word());
//else
//words[i] = wordIndex.indexOf(Lexicon.UNKNOWN_WORD);
}
for (int head = 0; head < length; head++) {
for (int tag = 0; tag < numTags; tag++) {
Arrays.fill(iScoreH[head][tag], Float.NEGATIVE_INFINITY);
Arrays.fill(oScoreH[head][tag], Float.NEGATIVE_INFINITY);
if (doiScoreHSum) {
Arrays.fill(iScoreHSum[head][tag], Float.NEGATIVE_INFINITY);
}
}
}
for (int head = 0; head < length; head++) {
for (int loc = 0; loc <= length; loc++) {
rawDistance[head][loc] = (head >= loc ? head - loc : loc - head - 1);
binDistance[head][loc] = dg.distanceBin(rawDistance[head][loc]);
}
}
if (Thread.interrupted()) {
throw new RuntimeInterruptedException();
}
// do tags
for (int start = 0; start + 1 <= length; start++) {
//Force tags
String trueTagStr = null;
if (sentence.get(start) instanceof HasTag) {
trueTagStr = ((HasTag) sentence.get(start)).tag();
if ("".equals(trueTagStr)) {
trueTagStr = null;
}
}
//Word context (e.g., morphosyntactic info)
String wordContextStr = null;
if(sentence.get(start) instanceof HasContext) {
wordContextStr = ((HasContext) sentence.get(start)).originalText();
if("".equals(wordContextStr))
wordContextStr = null;
}
int word = words[start];
for (Iterator taggingI = lex.ruleIteratorByWord(word, start, wordContextStr); taggingI.hasNext();) {
IntTaggedWord tagging = taggingI.next();
if (trueTagStr != null) {
if (!tlp.basicCategory(tagging.tagString(tagIndex)).equals(trueTagStr)) {
continue;
}
}
float score = lex.score(tagging, start, wordIndex.get(tagging.word), wordContextStr);
//iScoreH[start][tag][start] = (op.dcTags ? (float)op.testOptions.depWeight*score : 0.0f);
if (score > Float.NEGATIVE_INFINITY) {
int tag = tagging.tag;
iScoreH[start][dg.tagBin(tag)][start] = 0.0f;
iScoreH[start][dg.tagBin(tag)][start + 1] = 0.0f;
if (doiScoreHSum) {
iScoreHSum[start][dg.tagBin(tag)][start] = 0.0f;
iScoreHSum[start][dg.tagBin(tag)][start+1] = 0.0f;
}
if (DEBUG) System.err.println("DepParser accepted tagging: " + wordIndex.get(tagging.word)+"|"+tagIndex.get(tagging.tag) + ", got score " + score);
}
}
}
for (int hWord = 0; hWord < length; hWord++) {
for (int hTag = 0; hTag < numTags; hTag++) {
hasTag[hWord][hTag] = (iScoreH[hWord][hTag][hWord] + iScoreH[hWord][hTag][hWord + 1] > Float.NEGATIVE_INFINITY);
Arrays.fill(headStop[hWord][hTag], Float.NEGATIVE_INFINITY);
for (int aWord = 0; aWord < length; aWord++) {
for (int dist = 0; dist < dg.numDistBins(); dist++) {
Arrays.fill(headScore[dist][hWord][hTag][aWord], Float.NEGATIVE_INFINITY);
}
}
}
}
// score and cache all pairs -- headScores and stops
//int hit = 0;
for (int hWord = 0; hWord < length; hWord++) {
for (int hTag = 0; hTag < numTags; hTag++) {
//Arrays.fill(headStopL[hWord][hTag], Float.NEGATIVE_INFINITY);
//Arrays.fill(headStopR[hWord][hTag], Float.NEGATIVE_INFINITY);
//Arrays.fill(headStop[hWord][hTag], Float.NEGATIVE_INFINITY);
if (!hasTag[hWord][hTag]) {
continue;
}
for (int split = 0; split <= length; split++) {
if (split <= hWord) {
headStop[hWord][hTag][split] = (float) dg.scoreTB(words[hWord], hTag, -2, -2, false, hWord - split);
//System.out.println("headstopL " + hWord +" " + hTag + " " + split + " " + headStopL[hWord][hTag][split]); // debugging
} else {
headStop[hWord][hTag][split] = (float) dg.scoreTB(words[hWord], hTag, -2, -2, true, split - hWord - 1);
//System.out.println("headstopR " + hWord +" " + hTag + " " + split + " " + headStopR[hWord][hTag][split]); // debugging
}
//hit++;
}
//Timing.tick("hWord: "+hWord+" hTag: "+hTag+" piddle count: "+hit);
for (int aWord = 0; aWord < length; aWord++) {
if (aWord == hWord) {
continue; // can't be argument of yourself
}
boolean leftHeaded = hWord < aWord;
int start;
int end;
if (leftHeaded) {
start = hWord + 1;
end = aWord + 1;
} else {
start = aWord + 1;
end = hWord + 1;
}
for (int aTag = 0; aTag < numTags; aTag++) {
if ( ! hasTag[aWord][aTag]) {
continue;
}
for (int split = start; split < end; split++) {
// Moved this stuff out two loops- GMA
// for (int split = 0; split <= length; split++) {
// if leftHeaded, go from hWord+1 to aWord
// else go from aWord+1 to hWord
// if ((leftHeaded && (split <= hWord || split > aWord)) ||
// ((!leftHeaded) && (split <= aWord || split > hWord)))
// continue;
int headDistance = rawDistance[hWord][split];
int binDist = binDistance[hWord][split];
headScore[binDist][hWord][hTag][aWord][aTag] = (float) dg.scoreTB(words[hWord], hTag, words[aWord], aTag, leftHeaded, headDistance);
//hit++;
if (DEBUG) {
System.err.println("Dep score head -> dep: " + wordIndex.get(words[hWord]) + "/" + tagIndex.get(hTag) + "[" + hWord + "] -> " + wordIndex.get(words[aWord]) + "/" + tagIndex.get(aTag) + "[" + aWord + "] split [" + split + "] = " + headScore[binDist][hWord][hTag][aWord][aTag]);
}
// skip other splits with same binDist
while (split + 1 < end && binDistance[hWord][split + 1] == binDist) {
split++;
}
} // end split
} // end aTag
} // end aWord
} // end hTag
} // end hWord
if (op.testOptions.verbose) {
Timing.tick("done.");
// displayHeadScores();
System.err.print("Starting insides...");
}
// do larger spans
for (int diff = 2; diff <= length; diff++) {
if (Thread.interrupted()) {
throw new RuntimeInterruptedException();
}
if (DEBUG_MORE) System.err.println("SPAN " + diff + ": score = headPrev + argLeft + argRight + dep + argLStop + argRStop");
for (int start = 0; start + diff <= length; start++) {
int end = start + diff;
// left extension
int endHead = end - 1;
for (int endTag = 0; endTag < numTags; endTag++) {
if ( ! hasTag[endHead][endTag]) {
continue;
}
// bestScore is max for iScoreH
float bestScore = Float.NEGATIVE_INFINITY;
for (int argHead = start; argHead < endHead; argHead++) {
for (int argTag = 0; argTag < numTags; argTag++) {
if (!hasTag[argHead][argTag]) {
continue;
}
float argLeftScore = iScoreH[argHead][argTag][start];
if (argLeftScore == Float.NEGATIVE_INFINITY) {
continue;
}
float stopLeftScore = headStop[argHead][argTag][start];
if (stopLeftScore == Float.NEGATIVE_INFINITY) {
continue;
}
for (int split = argHead + 1; split < end; split++) {
// short circuit if dependency is impossible
float depScore = headScore[binDistance[endHead][split]][endHead][endTag][argHead][argTag];
if (depScore == Float.NEGATIVE_INFINITY) {
continue;
}
float score = iScoreH[endHead][endTag][split] + argLeftScore + iScoreH[argHead][argTag][split] + depScore + stopLeftScore + headStop[argHead][argTag][split];
if (DEBUG_MORE) {
System.err.println("Left extend " + wordIndex.get(words[endHead]) + "/" + tagIndex.get(endTag) + "[" + endHead + "] -> " + wordIndex.get(words[argHead]) + "/" + tagIndex.get(argTag) + "[" + argHead + "](" + start + "," + split + ")");
System.err.println(" " + score + " = SUM " + iScoreH[endHead][endTag][split] + " " + argLeftScore + " " + iScoreH[argHead][argTag][split] + " " + depScore + " " + headStop[argHead][argTag][start] + " " + headStop[argHead][argTag][split]);
}
if (score > bestScore) {
bestScore = score;
}
} // end for split
// sum for iScoreHSum
if (doiScoreHSum) {
double p = Math.exp(iScoreHSum[endHead][endTag][start]);
for (int split = argHead + 1; split < end; split++) {
p += Math.exp(iScoreH[argHead][argTag][start] +
iScoreH[argHead][argTag][split] +
headScore[binDistance[endHead][split]][endHead][endTag][argHead][argTag] +
headStop[argHead][argTag][start] +
headStop[argHead][argTag][split]);
}
iScoreHSum[endHead][endTag][start] = (float)Math.log(p);
}
} // end for argTag : tags
} // end for argHead
iScoreH[endHead][endTag][start] = bestScore;
} // end for endTag : tags
// right extension
int startHead = start;
for (int startTag = 0; startTag < numTags; startTag++) {
if ( ! hasTag[startHead][startTag]) {
continue;
}
// bestScore is max for iScoreH
float bestScore = Float.NEGATIVE_INFINITY;
for (int argHead = start + 1; argHead < end; argHead++) {
for (int argTag = 0; argTag < numTags; argTag++) {
if (!hasTag[argHead][argTag]) {
continue;
}
float argRightScore = iScoreH[argHead][argTag][end];
if (argRightScore == Float.NEGATIVE_INFINITY) {
continue;
}
float stopRightScore = headStop[argHead][argTag][end];
if (stopRightScore == Float.NEGATIVE_INFINITY) {
continue;
}
for (int split = start + 1; split <= argHead; split++) {
// short circuit if dependency is impossible
float depScore = headScore[binDistance[startHead][split]][startHead][startTag][argHead][argTag];
if (depScore == Float.NEGATIVE_INFINITY) {
continue;
}
float score = iScoreH[startHead][startTag][split] + iScoreH[argHead][argTag][split] + argRightScore + depScore + stopRightScore + headStop[argHead][argTag][split];
if (DEBUG_MORE) {
System.err.println("Right extend " + wordIndex.get(words[startHead]) + "/" + tagIndex.get(startTag) + "[" + startHead + "] -> " + wordIndex.get(words[argHead]) + "/" + tagIndex.get(argTag) + "[" + argHead + "](" + split + "," + end + ")");
System.err.println(" " + score + " = SUM " + iScoreH[startHead][startTag][split] + " " + iScoreH[argHead][argTag][split] + " " + argRightScore + " " + depScore + " " + headStop[argHead][argTag][end] + " " + headStop[argHead][argTag][split]);
}
if (score > bestScore) {
bestScore = score;
}
}
// sum for iScoreHSum
if (doiScoreHSum) {
double p = Math.exp(iScoreHSum[startHead][startTag][end]);
for (int split = argHead + 1; split < end; split++) {
p += Math.exp(iScoreH[startHead][startTag][split] +
iScoreH[argHead][argTag][split] +
iScoreH[argHead][argTag][end] +
headScore[binDistance[startHead][split]][startHead][startTag][argHead][argTag] +
headStop[argHead][argTag][end] +
headStop[argHead][argTag][split]);
}
iScoreHSum[startHead][startTag][end] = (float)Math.log(p);
}
} // end for argTag: tags
} // end for argHead
iScoreH[startHead][startTag][end] = bestScore;
} // end for startTag: tags
} // end for start
} // end for diff (i.e., span)
int goalTag = dg.tagBin(tagIndex.indexOf(Lexicon.BOUNDARY_TAG));
if (op.testOptions.verbose) {
Timing.tick("done.");
System.err.println("Dep parsing " + length + " words (incl. stop): insideScore " + (iScoreH[length - 1][goalTag][0] + iScoreH[length - 1][goalTag][length]));
}
if ( ! op.doPCFG) {
return hasParse();
}
if (op.testOptions.verbose) {
System.err.print("Starting outsides...");
}
oScoreH[length - 1][goalTag][0] = 0.0f;
oScoreH[length - 1][goalTag][length] = 0.0f;
for (int diff = length; diff > 1; diff--) {
if (Thread.interrupted()) {
throw new RuntimeInterruptedException();
}
for (int start = 0; start + diff <= length; start++) {
int end = start + diff;
// left half
int endHead = end - 1;
for (int endTag = 0; endTag < numTags; endTag++) {
if (!hasTag[endHead][endTag]) {
continue;
}
for (int argHead = start; argHead < endHead; argHead++) {
for (int argTag = 0; argTag < numTags; argTag++) {
if (!hasTag[argHead][argTag]) {
continue;
}
for (int split = argHead; split <= endHead; split++) {
float subScore = (oScoreH[endHead][endTag][start] + headScore[binDistance[endHead][split]][endHead][endTag][argHead][argTag] + headStop[argHead][argTag][start] + headStop[argHead][argTag][split]);
float scoreRight = (subScore + iScoreH[argHead][argTag][start] + iScoreH[argHead][argTag][split]);
float scoreMid = (subScore + iScoreH[argHead][argTag][start] + iScoreH[endHead][endTag][split]);
float scoreLeft = (subScore + iScoreH[argHead][argTag][split] + iScoreH[endHead][endTag][split]);
if (scoreRight > oScoreH[endHead][endTag][split]) {
oScoreH[endHead][endTag][split] = scoreRight;
}
if (scoreMid > oScoreH[argHead][argTag][split]) {
oScoreH[argHead][argTag][split] = scoreMid;
}
if (scoreLeft > oScoreH[argHead][argTag][start]) {
oScoreH[argHead][argTag][start] = scoreLeft;
}
}
}
}
}
// right half
int startHead = start;
for (int startTag = 0; startTag < numTags; startTag++) {
if (!hasTag[startHead][startTag]) {
continue;
}
for (int argHead = startHead + 1; argHead < end; argHead++) {
for (int argTag = 0; argTag < numTags; argTag++) {
if (!hasTag[argHead][argTag]) {
continue;
}
for (int split = startHead + 1; split <= argHead; split++) {
float subScore = (oScoreH[startHead][startTag][end] + headScore[binDistance[startHead][split]][startHead][startTag][argHead][argTag] + headStop[argHead][argTag][split] + headStop[argHead][argTag][end]);
float scoreLeft = (subScore + iScoreH[argHead][argTag][split] + iScoreH[argHead][argTag][end]);
float scoreMid = (subScore + iScoreH[startHead][startTag][split] + iScoreH[argHead][argTag][end]);
float scoreRight = (subScore + iScoreH[startHead][startTag][split] + iScoreH[argHead][argTag][split]);
if (scoreLeft > oScoreH[startHead][startTag][split]) {
oScoreH[startHead][startTag][split] = scoreLeft;
}
if (scoreMid > oScoreH[argHead][argTag][split]) {
oScoreH[argHead][argTag][split] = scoreMid;
}
if (scoreRight > oScoreH[argHead][argTag][end]) {
oScoreH[argHead][argTag][end] = scoreRight;
}
}
}
}
}
}
}
if (op.testOptions.verbose) {
Timing.tick("done.");
System.err.print("Starting half-filters...");
}
for (int loc = 0; loc <= length; loc++) {
for (int head = 0; head < length; head++) {
Arrays.fill(iPossibleByL[loc][head], false);
Arrays.fill(iPossibleByR[loc][head], false);
Arrays.fill(oPossibleByL[loc][head], false);
Arrays.fill(oPossibleByR[loc][head], false);
}
}
if (Thread.interrupted()) {
throw new RuntimeInterruptedException();
}
for (int head = 0; head < length; head++) {
for (int tag = 0; tag < numTags; tag++) {
if (!hasTag[head][tag]) {
continue;
}
for (int start = 0; start <= head; start++) {
for (int end = head + 1; end <= length; end++) {
if (iScoreH[head][tag][start] + iScoreH[head][tag][end] > Float.NEGATIVE_INFINITY && oScoreH[head][tag][start] + oScoreH[head][tag][end] > Float.NEGATIVE_INFINITY) {
iPossibleByR[end][head][tag] = true;
iPossibleByL[start][head][tag] = true;
oPossibleByR[end][head][tag] = true;
oPossibleByL[start][head][tag] = true;
}
}
}
}
}
if (op.testOptions.verbose) {
Timing.tick("done.");
}
return hasParse();
}
public boolean hasParse() {
return getBestScore() > Float.NEGATIVE_INFINITY;
}
public double getBestScore() {
int length = sentence.size();
if (length > arraySize) {
return Float.NEGATIVE_INFINITY;
}
int goalTag = tagIndex.indexOf(Lexicon.BOUNDARY_TAG);
return iScore(0, length, length - 1, goalTag);
}
/**
* This displays a headScore matrix, which will be valid after parsing
* a sentence. Unclear yet whether this is valid/useful [cdm].
*/
public void displayHeadScores() {
int numTags = tagIndex.size();
System.out.println("---- headScore matrix (head x dep, best tags) ----");
System.out.print(StringUtils.padOrTrim("", 6));
for (int i = 0; i < words.length; i++) {
System.out.print(" " + StringUtils.padOrTrim(wordIndex.get(words[i]), 2));
}
System.out.println();
for (int hWord = 0; hWord < words.length; hWord++) {
System.out.print(StringUtils.padOrTrim(wordIndex.get(words[hWord]), 6));
int bigBD = -1, bigHTag = -1, bigATag = -1;
for (int aWord = 0; aWord < words.length; aWord++) {
// we basically just max of all the variables, but for distance > 0, we
// include a factor for generating something at distance 0, or else
// the result is too whacked out to be useful
float biggest = Float.NEGATIVE_INFINITY;
for (int bd = 0; bd < dg.numDistBins(); bd++) {
for (int hTag = 0; hTag < numTags; hTag++) {
/*
float penalty = 0.0f;
if (bd != 0) {
penalty = (float) dg.score(words[hWord], hTag, -2, -2, aWord > hWord, 0);
penalty = (float) Math.log(1.0 - Math.exp(penalty));
}
for (int aTag = 0; aTag < numTags; aTag++) {
if (headScore[bd][hWord][hTag][aWord][aTag] + penalty > biggest) {
biggest = headScore[bd][hWord][hTag][aWord][aTag] + penalty;
*/
for (int aTag = 0; aTag < numTags; aTag++) {
if (headScore[bd][hWord][dg.tagBin(hTag)][aWord][dg.tagBin(aTag)] > biggest) {
biggest = headScore[bd][hWord][dg.tagBin(hTag)][aWord][dg.tagBin(aTag)];
bigBD = bd;
bigHTag = hTag;
bigATag = aTag;
}
}
}
}
if (Float.isInfinite(biggest)) {
System.out.print(" " + StringUtils.padOrTrim("in", 2));
} else {
int score = Math.round(Math.abs(headScore[bigBD][hWord][dg.tagBin(bigHTag)][aWord][dg.tagBin(bigATag)]));
System.out.print(" " + StringUtils.padOrTrim(Integer.toString(score), 2));
}
}
System.out.println();
}
}
private static final double TOL = 1e-5;
private static boolean matches(double x, double y) {
return (Math.abs(x - y) / (Math.abs(x) + Math.abs(y) + 1e-10) < TOL);
}
/** Find the best (partial) parse within the parameter constraints.
* @param start Sentence index of start of span (fenceposts, from 0 up)
* @param end Sentence index of end of span (right side fencepost)
* @param hWord Sentence index of head word (left side fencepost)
* @param hTag Tag assigned to hWord
* @return The best parse tree within the parameter constraints
*/
private Tree extractBestParse(int start, int end, int hWord, int hTag) {
if (DEBUG) {
System.err.println("Span "+start+" to "+end+" word "+wordIndex.get(words[hWord])+"/"+hWord+" tag "+tagIndex.get(hTag)+"/"+hTag+" score "+iScore(start, end, hWord, hTag));
}
String headWordStr = wordIndex.get(words[hWord]);
String headTagStr = tagIndex.get(hTag);
Label headLabel = new CategoryWordTag(headWordStr, headWordStr, headTagStr);
int numTags = tagIndex.size();
// deal with span 1
if (end - start == 1) {
Tree leaf = tf.newLeaf(new Word(headWordStr));
return tf.newTreeNode(headLabel, Collections.singletonList(leaf));
}
// find backtrace
List children = new ArrayList();
double bestScore = iScore(start, end, hWord, hTag);
for (int split = start + 1; split < end; split++) {
int binD = binDistance[hWord][split];
if (hWord < split) {
for (int aWord = split; aWord < end; aWord++) {
for (int aTag = 0; aTag < numTags; aTag++) {
if (matches(iScore(start, split, hWord, hTag) + iScore(split, end, aWord, aTag) + headScore[binD][hWord][dg.tagBin(hTag)][aWord][dg.tagBin(aTag)] + headStop[aWord][dg.tagBin(aTag)][split] + headStop[aWord][dg.tagBin(aTag)][end], bestScore)) {
if (DEBUG) {
String argWordStr = wordIndex.get(words[aWord]);
String argTagStr = tagIndex.get(aTag);
System.err.println(headWordStr+"|"+headTagStr+" -> "+argWordStr+"|"+argTagStr+" "+bestScore);
}
// build it
children.add(extractBestParse(start, split, hWord, hTag));
children.add(extractBestParse(split, end, aWord, aTag));
return tf.newTreeNode(headLabel, children);
}
}
}
} else {
for (int aWord = start; aWord < split; aWord++) {
for (int aTag = 0; aTag < numTags; aTag++) {
if (matches(iScore(start, split, aWord, aTag) + iScore(split, end, hWord, hTag) + headScore[binD][hWord][dg.tagBin(hTag)][aWord][dg.tagBin(aTag)] + headStop[aWord][dg.tagBin(aTag)][start] + headStop[aWord][dg.tagBin(aTag)][split], bestScore)) {
if (DEBUG) {
String argWordStr = wordIndex.get(words[aWord]);
String argTagStr = tagIndex.get(aTag);
System.err.println(headWordStr+"|"+headTagStr+" -> "+argWordStr+"|"+argTagStr+" "+bestScore);
}
children.add(extractBestParse(start, split, aWord, aTag));
children.add(extractBestParse(split, end, hWord, hTag));
// build it
return tf.newTreeNode(headLabel, children);
}
}
}
}
}
System.err.println("Problem in ExhaustiveDependencyParser::extractBestParse");
return null;
}
private Tree flatten(Tree tree) {
if (tree.isLeaf() || tree.isPreTerminal()) {
return tree;
}
List newChildren = new ArrayList();
Tree[] children = tree.children();
for (Tree child : children) {
Tree newChild = flatten(child);
if (!newChild.isPreTerminal() && newChild.label().toString().equals(tree.label().toString())) {
newChildren.addAll(newChild.getChildrenAsList());
} else {
newChildren.add(newChild);
}
}
return tf.newTreeNode(tree.label(), newChildren);
}
/** Return the best dependency parse for a sentence. You must call
* parse() before a call to this method.
*
* Implementation note: the best parse is recalculated from the chart
* each time this method is called. It isn't cached.
*
* @return The best dependency parse for a sentence or null.
* The returned tree will begin with a binary branching node, the
* left branch of which is the dependency tree proper, and the right
* side of which contains a boundary word .$. which heads the
* sentence.
*/
public Tree getBestParse() {
if ( ! hasParse()) {
return null;
}
return flatten(extractBestParse(0, words.length, words.length - 1, tagIndex.indexOf(Lexicon.BOUNDARY_TAG)));
}
public ExhaustiveDependencyParser(DependencyGrammar dg, Lexicon lex, Options op, Index wordIndex, Index tagIndex) {
this.dg = dg;
this.lex = lex;
this.op = op;
this.tlp = op.langpack();
this.wordIndex = wordIndex;
this.tagIndex = tagIndex;
tf = new LabeledScoredTreeFactory();
}
private void createArrays(int length) {
iScoreH = oScoreH = headStop = iScoreHSum = null;
iPossibleByL = iPossibleByR = oPossibleByL = oPossibleByR = null;
headScore = null;
rawDistance = binDistance = null;
int tagNum = dg.numTagBins(); //tagIndex.size();
iScoreH = new float[length + 1][tagNum][length + 1];
oScoreH = new float[length + 1][tagNum][length + 1];
if (doiScoreHSum) {
iScoreHSum = new float[length + 1][tagNum][length + 1];
}
iPossibleByL = new boolean[length + 1][length + 1][tagNum];
iPossibleByR = new boolean[length + 1][length + 1][tagNum];
oPossibleByL = new boolean[length + 1][length + 1][tagNum];
oPossibleByR = new boolean[length + 1][length + 1][tagNum];
headScore = new float[dg.numDistBins()][length][tagNum][length][tagNum];
headStop = new float[length + 1][tagNum][length + 1];
rawDistance = new int[length + 1][length + 1];
binDistance = new int[length + 1][length + 1];
}
/** Get the exact k best parses for the sentence.
*
* @param k The number of best parses to return
* @return The exact k best parses for the sentence, with
* each accompanied by its score (typically a
* negative log probability).
*/
public List> getKBestParses(int k) {
throw new UnsupportedOperationException("Doesn't do k best yet");
}
/** Get a complete set of the maximally scoring parses for a sentence,
* rather than one chosen at random. This set may be of size 1 or larger.
*
* @return All the equal best parses for a sentence, with each
* accompanied by its score
*/
public List> getBestParses() {
throw new UnsupportedOperationException("Doesn't do best parses yet");
}
/** Get k good parses for the sentence. It is expected that the
* parses returned approximate the k best parses, but without any
* guarantee that the exact list of k best parses has been produced.
* If a class really provides k best parses functionality, it is
* reasonable to also return this output as the k good parses.
*
* @param k The number of good parses to return
* @return A list of k good parses for the sentence, with
* each accompanied by its score
*/
public List> getKGoodParses(int k) {
throw new UnsupportedOperationException("Doesn't do k good yet");
}
/** Get k parse samples for the sentence. It is expected that the
* parses are sampled based on their relative probability.
*
* @param k The number of sampled parses to return
* @return A list of k parse samples for the sentence, with
* each accompanied by its score
*/
public List> getKSampledParses(int k) {
throw new UnsupportedOperationException("Doesn't do k sampled yet");
}
}