java - 如何在 Opennlp 中训练 Chunker？

Question

我需要在 Opennlp 中训练 Chunker 以将训练数据分类为名词短语。我该如何进行？在线文档没有解释如何在没有命令行的情况下将其合并到程序中。它说要使用 en-chunker.train，但是你如何制作该文件？

编辑:@Alaye运行您在答案中提供的代码后，出现以下无法修复的错误:

Indexing events using cutoff of 5

    Computing event counts...  done. 3 events
Dropped event B-NP:[w_2=bos, w_1=bos, w0=He, w1=reckons, w2=., w_1=bosw0=He, w0=Hew1=reckons, t_2=bos, t_1=bos, t0=PRP, t1=VBZ, t2=., t_2=bost_1=bos, t_1=bost0=PRP, t0=PRPt1=VBZ, t1=VBZt2=., t_2=bost_1=bost0=PRP, t_1=bost0=PRPt1=VBZ, t0=PRPt1=VBZt2=., p_2=bos, p_1=bos, p_2=bosp_1=bos, p_1=bost_2=bos, p_1=bost_1=bos, p_1=bost0=PRP, p_1=bost1=VBZ, p_1=bost2=., p_1=bost_2=bost_1=bos, p_1=bost_1=bost0=PRP, p_1=bost0=PRPt1=VBZ, p_1=bost1=VBZt2=., p_1=bost_2=bost_1=bost0=PRP, p_1=bost_1=bost0=PRPt1=VBZ, p_1=bost0=PRPt1=VBZt2=., p_1=bosw_2=bos, p_1=bosw_1=bos, p_1=bosw0=He, p_1=bosw1=reckons, p_1=bosw2=., p_1=bosw_1=bosw0=He, p_1=bosw0=Hew1=reckons]
Dropped event B-VP:[w_2=bos, w_1=He, w0=reckons, w1=., w2=eos, w_1=Hew0=reckons, w0=reckonsw1=., t_2=bos, t_1=PRP, t0=VBZ, t1=., t2=eos, t_2=bost_1=PRP, t_1=PRPt0=VBZ, t0=VBZt1=., t1=.t2=eos, t_2=bost_1=PRPt0=VBZ, t_1=PRPt0=VBZt1=., t0=VBZt1=.t2=eos, p_2=bos, p_1=B-NP, p_2=bosp_1=B-NP, p_1=B-NPt_2=bos, p_1=B-NPt_1=PRP, p_1=B-NPt0=VBZ, p_1=B-NPt1=., p_1=B-NPt2=eos, p_1=B-NPt_2=bost_1=PRP, p_1=B-NPt_1=PRPt0=VBZ, p_1=B-NPt0=VBZt1=., p_1=B-NPt1=.t2=eos, p_1=B-NPt_2=bost_1=PRPt0=VBZ, p_1=B-NPt_1=PRPt0=VBZt1=., p_1=B-NPt0=VBZt1=.t2=eos, p_1=B-NPw_2=bos, p_1=B-NPw_1=He, p_1=B-NPw0=reckons, p_1=B-NPw1=., p_1=B-NPw2=eos, p_1=B-NPw_1=Hew0=reckons, p_1=B-NPw0=reckonsw1=.]
Dropped event O:[w_2=He, w_1=reckons, w0=., w1=eos, w2=eos, w_1=reckonsw0=., w0=.w1=eos, t_2=PRP, t_1=VBZ, t0=., t1=eos, t2=eos, t_2=PRPt_1=VBZ, t_1=VBZt0=., t0=.t1=eos, t1=eost2=eos, t_2=PRPt_1=VBZt0=., t_1=VBZt0=.t1=eos, t0=.t1=eost2=eos, p_2B-NP, p_1=B-VP, p_2B-NPp_1=B-VP, p_1=B-VPt_2=PRP, p_1=B-VPt_1=VBZ, p_1=B-VPt0=., p_1=B-VPt1=eos, p_1=B-VPt2=eos, p_1=B-VPt_2=PRPt_1=VBZ, p_1=B-VPt_1=VBZt0=., p_1=B-VPt0=.t1=eos, p_1=B-VPt1=eost2=eos, p_1=B-VPt_2=PRPt_1=VBZt0=., p_1=B-VPt_1=VBZt0=.t1=eos, p_1=B-VPt0=.t1=eost2=eos, p_1=B-VPw_2=He, p_1=B-VPw_1=reckons, p_1=B-VPw0=., p_1=B-VPw1=eos, p_1=B-VPw2=eos, p_1=B-VPw_1=reckonsw0=., p_1=B-VPw0=.w1=eos]
    Indexing...  done.
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
    at java.util.ArrayList.rangeCheck(ArrayList.java:653)
    at java.util.ArrayList.get(ArrayList.java:429)
    at opennlp.tools.ml.model.AbstractDataIndexer.sortAndMerge(AbstractDataIndexer.java:89)
    at opennlp.tools.ml.model.TwoPassDataIndexer.<init>(TwoPassDataIndexer.java:105)
    at opennlp.tools.ml.AbstractEventTrainer.getDataIndexer(AbstractEventTrainer.java:74)
    at opennlp.tools.ml.AbstractEventTrainer.train(AbstractEventTrainer.java:91)
    at opennlp.tools.ml.model.TrainUtil.train(TrainUtil.java:53)
at opennlp.tools.chunker.ChunkerME.train(ChunkerME.java:253)
at com.oracle.crm.nlp.CustomChunker2.main(CustomChunker2.java:91)
Sorting and merging events... Process exited with exit code 1.

(我的 en-chunker.train 只有样本数据集的前 2 行和最后一行。)您能告诉我为什么会发生这种情况以及如何解决吗？

EDIT2:我让 Chunker 开始工作，但是当我将训练集中的句子更改为您在答案中给出的句子以外的任何句子时，它会出错。你能告诉我为什么会这样吗？

Answer 1

如 Opennlp Documentation 中所述

训练数据的例句:

He        PRP  B-NP
reckons   VBZ  B-VP
the       DT   B-NP
current   JJ   I-NP
account   NN   I-NP
deficit   NN   I-NP
will      MD   B-VP
narrow    VB   I-VP
to        TO   B-PP
only      RB   B-NP
#         #    I-NP
1.8       CD   I-NP
billion   CD   I-NP
in        IN   B-PP
September NNP  B-NP
.         .    O

这就是您制作 en-chunk.train 文件的方式，您可以使用 CLI 创建相应的 .bin 文件:

$ opennlp ChunkerTrainerME -model en-chunker.bin -lang en -data en-chunker.train -encoding

或使用API​​

public class SentenceTrainer {
   public static void trainModel(String inputFile, String modelFile)
  throws IOException {
  Objects.nonNull(inputFile);
  Objects.nonNull(modelFile);

      MarkableFileInputStreamFactory factory = new MarkableFileInputStreamFactory(
        new File(inputFile));


    Charset charset = Charset.forName("UTF-8");
    ObjectStream<String> lineStream =
        new PlainTextByLineStream(new FileInputStream("en-chunker.train"),charset);
    ObjectStream<ChunkSample> sampleStream = new ChunkSampleStream(lineStream);

    ChunkerModel model;

    try {
      model = ChunkerME.train("en", sampleStream,
          new DefaultChunkerContextGenerator(), TrainingParameters.defaultParams());
    }
    finally {
      sampleStream.close();
    }

    OutputStream modelOut = null;
    try {
      modelOut = new BufferedOutputStream(new FileOutputStream(modelFile));
      model.serialize(modelOut);
    } finally {
      if (modelOut != null)
         modelOut.close();
      }
     }
    }

主要方法是:

public class Main {

public static void main(String args[]) throws IOException {
  String inputFile = "//path//to//data.train";
  String modelFile = "//path//to//.bin";

  SentenceTrainer.trainModel(inputFile, modelFile);
 }
}

引用:这个blog

希望这对您有所帮助!

PS:如上所述收集/写入 .txt 文件中的数据，并将其重命名为 .train 扩展名，甚至 trainingdata.txt 也可以。这就是您制作 .train 文件的方式。