提取中心名词

Question

我想知道我们如何提取中心名词？我使用了一个不起作用的选民解析器，但我想我必须使用依赖解析器。我运行了这个演示代码，但它给了我一个错误的答案。

public class dependencydemo {
  public static void main(String[] args) throws IOException {
    PrintWriter out;
    if (args.length > 1) {
      out = new PrintWriter(args[1]);
    } else {
      out = new PrintWriter(System.out);
    }



    StanfordCoreNLP pipeline = new StanfordCoreNLP();
    Annotation annotation;
    if (args.length > 0) {
      annotation = new       ` 
 Annotation(IOUtils.slurpFileNoExceptions(args[0]));`
    } else {
      annotation = new Annotation("Yesterday, I went to the Dallas `Country Club to play 25 cent Bingo.  While I was there I talked to my `friend Jim and we both agree that those people in Washington are `destroying our economy.");`
    }

    pipeline.annotate(annotation);
    pipeline.prettyPrint(annotation, out);


    List<CoreMap> sentences = `annotation.get(CoreAnnotations.SentencesAnnotation.class);`
    if (sentences != null && sentences.size() > 0) {
      CoreMap sentence = sentences.get(0);
      Tree tree = `sentence.get(TreeCoreAnnotations.TreeAnnotation.class);`
     // out.println();
    //  out.println("The first sentence parsed is:");
      tree.pennPrint(out);
    }
   }   

输出：

(ROOT
  (S
    (NP-TMP (NN Yesterday))
    (, ,)
    (NP (PRP I))
    (VP (VBD went)
      (PP (TO to)
        (NP (DT the) (NNP Dallas) (NNP Country) (NNP Club)))
      (S
        (VP (TO to)
          (VP (VB play)
            (S
              (NP (CD 25) (NN cent))
              (NP (NNP Bingo)))))))
    (. .)))

依赖关系：

root(ROOT-0, went-4)
tmod(went-4, Yesterday-1)
nsubj(went-4, I-3)
det(Club-9, the-6)
nn(Club-9, Dallas-7)
nn(Club-9, Country-8)
prep_to(went-4, Club-9)
aux(play-11, to-10)
xcomp(went-4, play-11)
num(cent-13, 25-12)
nsubj(Bingo-14, cent-13)
xcomp(play-11, Bingo-14)

我怎样才能从中提取中心名词？除了它似乎输出是不正确的。

Answer 1

你在评论中的解释给我的印象是，你想要所有名词短语的中心成分。使用CoreNLP很容易做到这一点。

1. 首先，找到所有名词短语。您可以使用一个简单的Tregex模式(参见Chris Manning's relevant answer).
2. You可以使用CoreNLP“中心查找器”来选择匹配名词短语的句法中心成分)来完成此操作。例如，参见the ModCollinsHeadFinder.

演示代码如下。

// Fetch a head finder.
HeadFinder hf = new PennTreebankLanguagePack().headFinder();

Tree myTree = ...
TregexPattern tPattern = TregexPattern.compile("NP");
TregexMatcher tMatcher = tPattern.matcher(myTree);
while (tMatcher.find()) {
  Tree nounPhrase = tMatcher.getMatch();

  Tree headConstituent = hf.determineHead(nounPhrase);
  System.out.println(headConstituent);
}