Examples with Tree edu.cmu.lti.chineseNLP.util.Tree used on opensource projects

Example 1 with Tree

use of edu.cmu.lti.chineseNLP.util.Tree in project lucida by claritylab.

the class EnglishFeatureExtractor method addSyntacticFeatures.

private static void addSyntacticFeatures(MutableInstance instance, List<Term> terms, String parseTree, Term focusTerm) {
    if (parseTree == null) {
        log.error("Syntactic parse of the question is null.");
        return;
    }
    Tree tree = TreeHelper.buildTree(parseTree, Tree.ENGLISH);
    // MAIN_VERB
    TreeHelper.markHeadNode(tree);
    String mainVerb = tree.getHeadWord();
    //mainVerb = WordnetInterface.getLemma("VERB",mainVerb);
    try {
        IndexWord word = Dictionary.getInstance().lookupIndexWord(POS.VERB, mainVerb);
        String lemma = null;
        if (word != null)
            lemma = word.getLemma();
        if (lemma != null)
            mainVerb = lemma;
    } catch (Exception e) {
        log.warn("Failed to get lemma for verb '" + mainVerb + "'", e);
    }
    if (mainVerb == null)
        mainVerb = "-";
    instance.addBinary(new Feature("MAIN_VERB" + "." + mainVerb));
    // WH_DET
    if (focusTerm != null && focusTerm.getText() != null) {
        String focus = focusTerm.getText();
        String question = "";
        for (Term term : terms) question += term.getText() + " ";
        question = question.trim();
        for (String ptrn : whPtrns) {
            Matcher m = Pattern.compile(ptrn + SPACE_PTRN + focus + REST_PTRN).matcher(question);
            if (m.matches()) {
                instance.addBinary(new Feature("WH_DET" + ".+"));
                break;
            }
        }
    }
    // FOCUS_ADJ
    Tree focusNode = TreeHelper.findFirstPreterminalWithPrecedingPreterminal(tree, "RB|JJ", "WRB");
    if (focusNode != null)
        instance.addBinary(new Feature("FOCUS_ADJ" + "." + focusNode.getHeadWord()));
}

Example 2 with Tree

use of edu.cmu.lti.chineseNLP.util.Tree in project lucida by claritylab.

the class EnglishFeatureExtractor method createInstance.

/**
     * Creates and populates an Instance from a QuestionAnalysis object.  All
     * features are binary features of one of the following types:</p>
     * 
     * Word-level features:
     * <ul>
     *   <li>UNIGRAM : individual words in the question
     *   <li>BIGRAM : pairs of adjacent words in the question
     *   <li>WH_WORD : the wh-word in the question if one exists
     * </ul>
     * 
     * Syntactic features:
     * <ul>
     *   <li>MAIN_VERB: the syntactic head of the sentence, as defined in 
     *   {@link edu.cmu.lti.chineseNLP.util.TreeHelper TreeHelper}
     *   <li>FOCUS_ADJ : the adjective following a wh-word (e.g. 'long' in 'How long is it?') 
     *   <li>WH_DET : whether or not the wh-word is the determiner of a noun phrase, as in 'which printer'
     * </ul>
     * 
     * Semantic features:
     * <ul>
     *   <li>FOCUS_TYPE : the semantic type of the focus word, 
     * </ul>
     * 
     * @throws Exception
     */
public Instance createInstance(List<Term> terms, String parseTree) {
    String question = "";
    for (Term term : terms) question += term + " ";
    question = question.trim();
    MutableInstance instance = new MutableInstance(question);
    // find the focus word
    log.debug("Parse: " + parseTree);
    Tree tree = TreeHelper.buildTree(parseTree, Tree.ENGLISH);
    Term focus = FocusFinder.findFocusTerm(tree);
    if (focus != null)
        log.debug("Focus: " + focus.getText());
    addWordLevelFeatures(instance, terms, focus);
    addSyntacticFeatures(instance, terms, parseTree, focus);
    addSemanticFeatures(instance, focus);
    return instance;
}

Example 3 with Tree

use of edu.cmu.lti.chineseNLP.util.Tree in project lucida by claritylab.

the class FocusFinder method findFocusNode.

/**
     * Finds the focus, or target, word of a question using the specified tree
     * templates and default rules that look for question words.</p>
     * 
     * Using the following algorithm:</p>
     * <ol>
     *   <li> Look for the head word of a phrase that has a wh-word child and 
     *   more than one sibling
     *   <ul>
     *     <li> look for the object of a modifying of-<code>PP</code> if the word
     *      is "kind" or "type"
     *   </ul>
     *   <li> Try to extract a node using the specified tree templates in the order 
     *   they appear in the file
     *   <li> Using only preterminals, look for the last consecutive <code>NN*</code> 
     *   or <code>JJ</code> that follows a <code>WDT</code> or <code>WP</code>
     *   <li> Using only preterminals, look for the last consecutive <code>NN*</code> 
     *   that follows the terminals, "how many".   
     * </ol>
     * 
     * the focus word is returned as soon as one is found.</p>
     * 
     * @param tree The syntactic parse tree of the question
     * @return the focus word, or <code>null</code> if none was found
     */
public static Tree findFocusNode(Tree tree) {
    Tree focus = null;
    TreeHelper.markHeadNode(tree);
    // look for a WH word with siblings anywhere in the tree
    for (String whLabel : whLabels) {
        Tree whPhrase = TreeHelper.findNodeWithChild(tree, whLabel);
        if (whPhrase != null && whPhrase.numOfChildren() > 1 && !whPhrase.getLabel().equals("SBAR")) {
            Tree head = getHeadWordOrPhrase(whPhrase);
            TreeHelper.markHeadNode(head);
            String headStr = head.getHeadWord();
            if (headStr.matches("kinds?") || headStr.matches("types?") || headStr.matches("genres?")) {
                Tree headNode = whPhrase.getHeadNode();
                Tree parent = TreeHelper.locateParent(headNode, tree);
                Tree pp = parent.getChild("PP");
                if (pp == null && parent.getLabel().matches("WHNP|NP")) {
                    Tree grandParent = TreeHelper.locateParent(parent, tree);
                    pp = grandParent.getChild("PP");
                }
                if (pp != null && pp.getChild("IN").getHeadWord().equals("of")) {
                    focus = getHeadWordOrPhrase(pp.getChild("NP"));
                    break;
                }
            }
            if (head.getLabel().equals("POS")) {
                if (whPhrase.numOfChildren() > 2)
                    return getHeadWordOrPhrase(whPhrase.getChild(whPhrase.getHeadNodeChildIndex() - 1));
            }
            return head;
        }
    }
    if (focus != null)
        return focus;
    // use syntactic patterns for when the focus word is apart from the WH word.
    for (Tree template : treeTemplates) {
        Tree node = TreeHelper.extractNode(tree, template);
        if (node == null)
            continue;
        focus = getHeadWordOrPhrase(node);
        if (focus != null)
            return focus;
    }
    //  look for a JJ or last consecutive NN preceded by WDT
    List<Tree> nodes = TreeHelper.getPreterminalsAfter(tree, "NN.?|JJ", "WDT");
    if (nodes == null)
        nodes = TreeHelper.getPreterminalsAfter(tree, "NN.?|JJ", "WP");
    if (nodes != null) {
        focus = Tree.newNode("NP", nodes);
        return getHeadWordOrPhrase(focus);
    }
    // look for a NN* preceded by 'how many'
    List<Tree> tags = TreeHelper.getPreterminals(tree).asList();
    nodes = new ArrayList<Tree>();
    for (ListIterator<Tree> it = tags.listIterator(); it.hasNext(); ) {
        Tree tag = it.next();
        if (tag.getHeadWord().toLowerCase().equals("how") && it.next().getHeadWord().toLowerCase().matches("many|much")) {
            for (ListIterator<Tree> it2 = tags.listIterator(it.nextIndex()); it2.hasNext() && it2.next().getLabel().matches("NN.?"); ) {
                nodes.add(tags.get(it2.previousIndex()));
            }
            break;
        }
    }
    if (nodes.size() > 0) {
        focus = Tree.newNode("NP", nodes);
        return getHeadWordOrPhrase(focus);
    }
    return null;
}

Example 4 with Tree

use of edu.cmu.lti.chineseNLP.util.Tree in project lucida by claritylab.

the class FocusFinder method findFocusTerm.

/**
     * Given a list of Terms, builds a parse tree using Charniak's parser, and 
     * then uses the resulting parse tree to find the focus words.
     * 
     * @param terms The list of Terms in the question.
     * @return the focus word as a Term or null, if one does not exist
     */
public static Term findFocusTerm(List<Term> terms) {
    try {
        String question = "";
        for (Term term : terms) {
            question += term + " ";
        }
        Tree t = findFocusNode(TreeHelper.buildTree(StanfordParser.parse(question), Tree.ENGLISH));
        if (t != null) {
            Term res = new Term(0, 0, TreeHelper.getLeaves(t));
            res.setPOS(t.getLabel());
            return res;
        }
        return null;
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

Example 5 with Tree

use of edu.cmu.lti.chineseNLP.util.Tree in project lucida by claritylab.

the class FocusFinder method findFocusWord.

/**
     * Given a list of Terms, builds a parse tree using Charniak's parser, and 
     * then uses the resulting parse tree to find the focus words.
     * 
     * @param terms The list of Terms in the question.
     * @return the focus word as a String or null, if one does not exist
     */
public static String findFocusWord(List<Term> terms) {
    try {
        String question = "";
        for (Term term : terms) {
            question += term + " ";
        }
        Tree t = findFocusNode(TreeHelper.buildTree(StanfordParser.parse(question), Tree.ENGLISH));
        if (t != null)
            return TreeHelper.getLeaves(t);
        return null;
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}