Package edu.stanford.nlp.ie

Class ClassifierCombiner<IN extends CoreMap & HasWord>

java.lang.Object

edu.stanford.nlp.ie.AbstractSequenceClassifier<IN>

edu.stanford.nlp.ie.ClassifierCombiner<IN>

All Implemented Interfaces:

Function<String,String>

Direct Known Subclasses:

NERClassifierCombiner

public class ClassifierCombiner<IN extends CoreMap & HasWord>
extends AbstractSequenceClassifier<IN>

Merges the outputs of two or more AbstractSequenceClassifiers according to a simple precedence scheme: any given base classifier contributes only classifications of labels that do not exist in the base classifiers specified before, and that do not have any token overlap with labels assigned by higher priority classifiers.

This is a pure AbstractSequenceClassifier, i.e., it sets the AnswerAnnotation label. If you work with NER classifiers, you should use NERClassifierCombiner. This class inherits from ClassifierCombiner, and takes care that all AnswerAnnotations are also copied to NERAnnotation.

You can specify up to 10 base classifiers using the -loadClassifier1 to -loadClassifier10 properties. We also maintain the older usage when only two base classifiers were accepted, specified using -loadClassifier and -loadAuxClassifier.

ms 2009: removed all NER functionality (see NERClassifierCombiner), changed code so it accepts an arbitrary number of base classifiers, removed dead code.

Author:

Chris Cox, Mihai Surdeanu

Field Summary

Fields inherited from class edu.stanford.nlp.ie.AbstractSequenceClassifier

classIndex, featureFactories, flags, knownLCWords, pad, windowSize

Constructor Summary

Constructors

Constructor	Description
ClassifierCombiner(AbstractSequenceClassifier<IN>... classifiers)	Combines a series of base classifiers.
ClassifierCombiner(edu.stanford.nlp.ie.ClassifierCombiner.CombinationMode combinationMode, String... loadPaths)	Loads a series of base classifiers from the paths specified using the Properties specified.
ClassifierCombiner(ObjectInputStream ois, Properties props)
ClassifierCombiner(String... loadPaths)	Loads a series of base classifiers from the paths specified.
ClassifierCombiner(Properties p)
ClassifierCombiner(Properties props, edu.stanford.nlp.ie.ClassifierCombiner.CombinationMode combinationMode, String... loadPaths)	Loads a series of base classifiers from the paths specified using the Properties specified.

Method Summary

Modifier and Type	Method	Description
List<IN>	classify(List<IN> tokens)	Generates the AnswerAnnotation labels of the combined model for the given tokens, storing them in place in the tokens.
List<IN>	classifyWithGlobalInformation(List<IN> tokenSeq, CoreMap doc, CoreMap sent)	Classify a List of something that extends CoreMap using as additional information whatever is stored in the document and sentence.
static void	examineCRF(ClassifierCombiner cc, String crfNameOrIndex, SeqClassifierFlags flags, String testFile, String testFiles, DocumentReaderAndWriter<CoreLabel> readerAndWriter)
static edu.stanford.nlp.ie.ClassifierCombiner.CombinationMode	extractCombinationMode(Properties p)	Either finds COMBINATION_MODE_PROPERTY or returns a default value.
static edu.stanford.nlp.ie.ClassifierCombiner.CombinationMode	extractCombinationModeSafe(Properties p)	Either finds COMBINATION_MODE_PROPERTY or returns a default value.
static ClassifierCombiner	getClassifier(ObjectInputStream ois, Properties props)
static ClassifierCombiner	getClassifier(String loadPath, Properties props)
Set<String>	labels()
void	loadClassifier(ObjectInputStream in, Properties props)	Load a classifier from the specified input stream.
static <INN extends CoreMap & HasWord> AbstractSequenceClassifier<INN>	loadClassifierFromPath(Properties props, String path)
static void	main(String[] args)	Some basic testing of the ClassifierCombiner.
void	serializeClassifier(ObjectOutputStream oos)	Serialize a sequence classifier to an object output stream
void	serializeClassifier(String serializePath)	Serialize a sequence classifier to a file on the given path.
static void	showCCInfo(ClassifierCombiner cc)
void	train(Collection<List<IN>> docs, DocumentReaderAndWriter<IN> readerAndWriter)	Trains a classifier from a Collection of sequences.

Methods inherited from class edu.stanford.nlp.ie.AbstractSequenceClassifier

apply, backgroundSymbol, classify, classifyAndWriteAnswers, classifyAndWriteAnswers, classifyAndWriteAnswers, classifyAndWriteAnswers, classifyAndWriteAnswers, classifyAndWriteAnswers, classifyAndWriteAnswers, classifyAndWriteAnswersKBest, classifyAndWriteAnswersKBest, classifyAndWriteViterbiSearchGraph, classifyFile, classifyFilesAndWriteAnswers, classifyFilesAndWriteAnswers, classifyKBest, classifyRaw, classifySentence, classifySentenceWithGlobalInformation, classifyStdin, classifyStdin, classifyToCharacterOffsets, classifyToString, classifyToString, classifyWithInlineXML, countResults, countResultsSegmenter, defaultReaderAndWriter, dumpFeatures, finalizeClassification, getKnownLCWords, getSampler, getSequenceModel, loadClassifier, loadClassifier, loadClassifier, loadClassifier, loadClassifier, loadClassifier, loadClassifierNoExceptions, loadClassifierNoExceptions, loadClassifierNoExceptions, loadClassifierNoExceptions, loadClassifierNoExceptions, makeObjectBankFromFile, makeObjectBankFromFile, makeObjectBankFromFiles, makeObjectBankFromFiles, makeObjectBankFromFiles, makeObjectBankFromReader, makeObjectBankFromString, makePlainTextReaderAndWriter, makePlainTextReaderAndWriter, makeReaderAndWriter, plainTextReaderAndWriter, printFeatureLists, printFeatures, printProbs, printProbs, printProbsDocument, printProbsDocuments, printResults, reinit, segmentString, segmentString, train, train, train, train, train, train, windowSize, writeAnswers

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.function.Function

andThen, compose

Constructor Detail

ClassifierCombiner

public ClassifierCombiner(Properties p)
                   throws IOException

Parameters:

p - Properties File that specifies loadClassifier and loadAuxClassifier properties or, alternatively, loadClassifier[1-10] properties.

Throws:

FileNotFoundException - If classifier files not found

IOException

ClassifierCombiner

public ClassifierCombiner(Properties props,
                          edu.stanford.nlp.ie.ClassifierCombiner.CombinationMode combinationMode,
                          String... loadPaths)
                   throws IOException

Loads a series of base classifiers from the paths specified using the Properties specified.

Parameters:

props - Properties for the classifier to use (encodings, output format, etc.)

combinationMode - How to handle multiple classifiers specifying the same entity type

loadPaths - Paths to the base classifiers

Throws:

IOException - If IO errors in loading classifier files

ClassifierCombiner

public ClassifierCombiner(edu.stanford.nlp.ie.ClassifierCombiner.CombinationMode combinationMode,
                          String... loadPaths)
                   throws IOException

Loads a series of base classifiers from the paths specified using the Properties specified.

Parameters:

combinationMode - How to handle multiple classifiers specifying the same entity type

loadPaths - Paths to the base classifiers

Throws:

IOException - If IO errors in loading classifier files

ClassifierCombiner

public ClassifierCombiner(String... loadPaths)
                   throws IOException

Loads a series of base classifiers from the paths specified.

Parameters:

loadPaths - Paths to the base classifiers

Throws:

FileNotFoundException - If classifier files not found

IOException

ClassifierCombiner

@SafeVarargs
public ClassifierCombiner(AbstractSequenceClassifier<IN>... classifiers)

Combines a series of base classifiers.

Parameters:

classifiers - The base classifiers

ClassifierCombiner

public ClassifierCombiner(ObjectInputStream ois,
                          Properties props)
                   throws IOException,
                          ClassNotFoundException,
                          ClassCastException

Throws:

IOException

ClassNotFoundException

ClassCastException

Method Detail

extractCombinationMode

public static edu.stanford.nlp.ie.ClassifierCombiner.CombinationMode extractCombinationMode(Properties p)

Either finds COMBINATION_MODE_PROPERTY or returns a default value.

extractCombinationModeSafe

public static edu.stanford.nlp.ie.ClassifierCombiner.CombinationMode extractCombinationModeSafe(Properties p)

Either finds COMBINATION_MODE_PROPERTY or returns a default value. If the value is not a legal value, a warning is printed.

loadClassifierFromPath

public static <INN extends CoreMap & HasWord> AbstractSequenceClassifier<INN> loadClassifierFromPath(Properties props,
                                                                                                     String path)
                                                                                              throws IOException

Throws:

IOException

labels

public Set<String> labels()

Overrides:

labels in class AbstractSequenceClassifier<IN extends CoreMap & HasWord>

classify

public List<IN> classify(List<IN> tokens)

Generates the AnswerAnnotation labels of the combined model for the given tokens, storing them in place in the tokens.

Specified by:

classify in class AbstractSequenceClassifier<IN extends CoreMap & HasWord>

Parameters:

tokens - A List of IN

Returns:

The passed in parameters, which will have the AnswerAnnotation field added/overwritten

train

public void train(Collection<List<IN>> docs,
                  DocumentReaderAndWriter<IN> readerAndWriter)

Description copied from class: AbstractSequenceClassifier

Trains a classifier from a Collection of sequences. Note that the Collection can be (and usually is) an ObjectBank.

Specified by:

train in class AbstractSequenceClassifier<IN extends CoreMap & HasWord>

Parameters:

docs - An ObjectBank or a collection of sequences of IN

readerAndWriter - A DocumentReaderAndWriter to use when loading test files

serializeClassifier

public void serializeClassifier(String serializePath)

Description copied from class: AbstractSequenceClassifier

Serialize a sequence classifier to a file on the given path.

Specified by:

serializeClassifier in class AbstractSequenceClassifier<IN extends CoreMap & HasWord>

Parameters:

serializePath - The path/filename to write the classifier to.

serializeClassifier

public void serializeClassifier(ObjectOutputStream oos)

Description copied from class: AbstractSequenceClassifier

Serialize a sequence classifier to an object output stream

Specified by:

serializeClassifier in class AbstractSequenceClassifier<IN extends CoreMap & HasWord>

loadClassifier

public void loadClassifier(ObjectInputStream in,
                           Properties props)
                    throws IOException,
                           ClassCastException,
                           ClassNotFoundException

Description copied from class: AbstractSequenceClassifier

Load a classifier from the specified input stream. The classifier is reinitialized from the flags serialized in the classifier.

Specified by:

loadClassifier in class AbstractSequenceClassifier<IN extends CoreMap & HasWord>

Parameters:

in - The InputStream to load the serialized classifier from

props - This Properties object will be used to update the SeqClassifierFlags which are read from the serialized classifier

Throws:

IOException - If there are problems accessing the input stream

ClassCastException - If there are problems interpreting the serialized data

ClassNotFoundException - If there are problems interpreting the serialized data

classifyWithGlobalInformation

public List<IN> classifyWithGlobalInformation(List<IN> tokenSeq,
                                              CoreMap doc,
                                              CoreMap sent)

Description copied from class: AbstractSequenceClassifier

Classify a List of something that extends CoreMap using as additional information whatever is stored in the document and sentence. This is needed for SUTime (NumberSequenceClassifier), which requires the document date to resolve relative dates.

Specified by:

classifyWithGlobalInformation in class AbstractSequenceClassifier<IN extends CoreMap & HasWord>

Parameters:

tokenSeq - A List of something that extends CoreMap

Returns:

Classified version of the input tokenSequence

getClassifier

public static ClassifierCombiner getClassifier(String loadPath,
                                               Properties props)
                                        throws IOException,
                                               ClassNotFoundException,
                                               ClassCastException

Throws:

IOException

ClassNotFoundException

ClassCastException

getClassifier

public static ClassifierCombiner getClassifier(ObjectInputStream ois,
                                               Properties props)
                                        throws IOException,
                                               ClassCastException,
                                               ClassNotFoundException

Throws:

IOException

ClassCastException

ClassNotFoundException

examineCRF

public static void examineCRF(ClassifierCombiner cc,
                              String crfNameOrIndex,
                              SeqClassifierFlags flags,
                              String testFile,
                              String testFiles,
                              DocumentReaderAndWriter<CoreLabel> readerAndWriter)
                       throws Exception

Throws:

Exception

showCCInfo

public static void showCCInfo(ClassifierCombiner cc)

main

public static void main(String[] args)
                 throws Exception

Some basic testing of the ClassifierCombiner.

Parameters:

args - Command-line arguments as properties: -loadClassifier1 serializedFile -loadClassifier2 serializedFile

Throws:

Exception - If IO or serialization error loading classifiers