conceptdriftsimulator.java

著名的开源仿真软件yale

    private int           noOfBatches, currentBatch;
    private int           noOfStreams;                // no. of input data streams (e.g. no. of topic of text documents)
    private int           noOfExamples;               // total no. of examples (e.g. documents) in the input example set
    private int           batchSize;                  // no. of documents per batch (evenly distributed, left overs discarded)

    private String[]      streamNames;
    private double[][]    streamRelevance;            // streamRelevance[s][b] = probability for an example from stream 's'
                                                      //                         to be relevant in batch 'b'

    private int[]         timeIndex2example;          // maps a time point to the example (e.g. document) at that time point
    private int[]         example2timeIndex;          // maps an example (e.g. document) to a time point
    private int[]         example2batchIndex;         // maps an example (e.g. document) to a batch
    private int[]         example2label;              // maps an example (e.g. document) to its (user interest) label
    private int[]         example2streamIndex;        // example2streamIndex[e] = index of the stream the example 'e' comes from
    private int[][]       noOfStreamExamplesInBatch;  // noOfStreamExamplesInBatch[s][b] = no. of examples from stream 's'
                                                      //                                   in batch 'b'
    private int[]         noOfExamplesInBatch;        // noOfExamplesInBatch[b] = no. of examples in batch 'b'

    private int           learnerType;          // type of enclosed learner (static vs. static window vs. adaptive)
    private int           timeWindowSize;       // window size in case of a static window learner (window of fixed size)

    private static final int  ILLEGAL_STREAM_INDEX = -1;

    public ConceptDriftSimulator() {
	// Make the number of the current run of this operator, which starts with 1 and 
	// goes up to 'noOfRuns' (= parameter 'number_of_runs'), and which can for example
	// be used to monitor the progress of this operator, externally accessible:
	addValue(new Value("run", "The number of the current run.") {
		public double getValue() {
		    return currentRun;
		}
	    });
    }

    /** returns the the classes this operator expects as input. */
    public Class[] getInputClasses() { return INPUT_CLASSES; }
    /** returns the the classes this operator provides as output. */
    public Class[] getOutputClasses() { return OUTPUT_CLASSES; }


    // ==== apply() : Concept Drift Simulation ====
    //
    public IOObject[] apply() throws OperatorException {

	// #### initialize ####
	LogService.logMessage("ConceptDriftSimulator '" + getName() + "': prepare concept drift simulation", LogService.TASK);

	// ---- retrieve the operator input objects ----
	IOContainer  input = getInput();                                     // operator input objects
	inputSet           = (ExampleSet)input.getInput(ExampleSet.class);   // input example set
	exampleSet         = (ExampleSet)inputSet.clone();                   // internal copy of the input example set

	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': old label attribute = "+inputSet.getLabel(), LogService.TASK);

	// ---- retrieve the operator parameters (no. of runs, no. of batches, data streams) ----
	noOfRuns    = getParameterAsInt("number_of_runs");     // min. 2 runs, default 10 runs
	noOfBatches = getParameterAsInt("number_of_batches");  // min. 2 batches, default 10 batches
	noOfStreams = getParameterAsInt("number_of_streams");  // min. 2 streams, default 2 streams
	// data_stream_relevance[s][b] = probability of a document of stream 's' (= Topic t) to be relevant in batch 'b')
	streamNames     = new String[noOfStreams];
	streamRelevance = new double[noOfStreams][noOfBatches];
	String  streamNamesString     = getParameterAsString("data_stream_names");
	scanStreamNames (streamNames, streamNamesString);
	String  streamRelevanceString = getParameterAsString("data_stream_relevance");
	scanStreamRelevanceSpecification (streamRelevance, streamRelevanceString, streamNames, exampleSet);
	// ---- compute further variables ----
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': check example set", LogService.TASK);
	noOfExamples = (exampleSet.getSize());
	batchSize    = ((int) (((double) noOfExamples) / ((double) noOfBatches)));
	// sanity check:  min. 2 batches, min. 1 example per batch (=> min. 2 examples):
	if (noOfBatches < 2) {
	    throw new FatalException("ConceptDriftSimulator '"+getName()+"': There must be at least 2 batches " +
				     "for a concept drift simulation (here "+noOfBatches+" batches).");
	}
	if (batchSize < 1) {
    	    throw new FatalException("ConceptDriftSimulator '"+getName()+"': There must be at least as many examples as " +
				     "batches for a concept drift simulation (here "+noOfExamples+" examples are to be " +
				     "distributed to " + noOfBatches + " batches).");
	}

	// ---- retrieve the operator parameters (learner type, window size) ----
	learnerType    = getParameterAsInt ("learner_type");
	timeWindowSize = getParameterAsInt ("window_size");

	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': create new attributes", LogService.TASK);
        // #### add new attributes to example set:  [stream[_index]], time_index, batch_index, weight, user_interest ####
	// #### (and set 'stream', 'time_index', and 'batch_index' to 'unused')                                      ####
	// keep old class labels (= data stream names) in a new attribute before dropping the old class label:
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': get old label attribute", LogService.TASK);
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': old label = "+exampleSet.getLabel(), LogService.TASK);
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': clone old label attribute", LogService.TASK);
	streamNameAttribute = (Attribute) (exampleSet.getLabel()).clone();
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': create stream name attribute (= clone of old label)", LogService.TASK);
	streamNameAttribute.setName (Attribute.createName("stream_name"));
	// exampleSet.appendAttributeReference (new AttributeReference (streamNameAttribute,false));
	//// create special weight attribute (get /set values via Example.getWeight /.setWeight):
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': create weight attribute", LogService.TASK);
	exampleSet.createWeightAttribute();
	//// create new attributes for the time index and the batch index of an example:
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': create time index attribute", LogService.TASK);
	timeIndexAttribute = new Attribute (Attribute.createName("time_index"),                  // create new attribute
					    Ontology.INTEGER, Ontology.SINGLE_VALUE,
					    Attribute.UNDEFINED_BLOCK_NR, null);
	(exampleSet.getExampleTable()).addAttribute(timeIndexAttribute);                         // create example table column
	// exampleSet.appendAttributeReference (new AttributeReference (timeIndexAttribute,false)); // register ref. in example set
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': create batch index attribute", LogService.TASK);
	batchIndexAttribute = new Attribute (Attribute.createName("batch_index"),
					     Ontology.INTEGER, Ontology.SINGLE_VALUE,
					     Attribute.UNDEFINED_BLOCK_NR, null);
	(exampleSet.getExampleTable()).addAttribute(batchIndexAttribute);
	// exampleSet.appendAttributeReference (new AttributeReference (batchIndexAttribute,false));
	//// create new attribute for the new class labels (= simulated user interest):
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': create new label attribute", LogService.TASK);
	userInterestAttribute = new Attribute (Attribute.createName("user_interest"),
					       Ontology.CLASSIFICATION, Ontology.SINGLE_VALUE,
					       Attribute.UNDEFINED_BLOCK_NR, null);
	(exampleSet.getExampleTable()).addAttribute(userInterestAttribute);

	//// exampleSet.appendAttributeReference (new AttributeReference (userInterestAttribute,true));
	////// change class label attribute from stream name (original) to user interest (new):
	/* TMP/2003/04/30 */ LogService.logMessage("ConceptDriftSimulator '" + getName() + "': set new label attribute", LogService.TASK);
	exampleSet.setLabel (userInterestAttribute);

	LogService.logMessage("ConceptDriftSimulator '" + getName() + "': start concept drift simulation", LogService.TASK);

	// #### loop for runs ####
	BatchedExampleSet  currentExampleSet;                             // current ExampleSet
	// performance result data structures:
	SeriesVector       performanceResultMatrix = new SeriesVector();  // results of all batches for all runs
	RunVector          singleRunResults;                              // result time series of a single run
	RunVector          averagedTimeSeriesResults;                     // average result time series, averaged over all runs
	PerformanceVector  averagedOverallResults;                        // overall result averaged over all runs and batches
	for (int run = 0; run < noOfRuns; run++) {
	    singleRunResults = new RunVector();

	    // #### sample example2batch and example2class ####
	    sampleExamples2Batches();
	    sampleExamples2Labels();

	    // #### loop for batches ####
	    // Training set:  batches 0..b-1  (for induction)  (vs.: for transduction also batch b, but without labels)
	    // Test set:      batch   b
	    for (int batch = 1; batch < noOfBatches; batch++) {
		LogService.logMessage("ConceptDriftSimulator '" + getName() + "': current run = " + (run+1) + 
				      ", current batch = " + batch + "\n", LogService.TASK);

		// ---- prepare training set ----
		// induction:
		int  firstBatch = 0;
		switch (learnerType) {
		case STATIC_WINDOW_LEARNER :
		    firstBatch = maximumInt (0, batch-timeWindowSize);
		    break;
		case STATIC_LEARNER :
		case ADAPTIVE_LEARNER :
		default :
		    firstBatch = 0;
		}
		currentExampleSet = new BatchedExampleSet (exampleSet, batchIndexAttribute, firstBatch, batch-1);
                //
		// // transduction:
		// currentExampleSet = new BatchedExampleSet (exampleSet, batchIndexAttribute, firstBatch, batch);
		// // ... for transduction: clone label and set to unlabeled for last batch

		// ---- call learning chain ----
		// ((SVMLearner)((OperatorChain)this.getOperator(0)).getOperator(0)).setPositiveLabelIndex((int)userInterestAttribute.mapString(Attribute.POSITIVE_CLASS));  // TMP: HACK !!!
		learn((ExampleSet)currentExampleSet);

		// if (learnerType == ADAPTIVE_LEARNER) :  BatchLearner < Learner,
		//	 learn(currentExampleSet,batchIndexAttribute,firstBatch,currentBatch,lastBatch)
		//    or learn(currentExampleSet) with getBatchIndexAttribute(), getFirstBatch(), getLastBatch();

		// ---- prepare test set ----
		currentExampleSet = new BatchedExampleSet (exampleSet, batchIndexAttribute, batch, batch);

		// ---- call applier and performance evaluator chain and get its output ----
		IOContainer evalOutput = evaluate(currentExampleSet);

		//// read results
		PerformanceVector  currentResults = (PerformanceVector)evalOutput.getInput(PerformanceVector.class);  
		setLastPerformance(currentResults.getMainCriterion());
		singleRunResults.add(currentResults);

		inApplyLoop();  // for GNU-Plot-Service
	    }

	    performanceResultMatrix.add(singleRunResults);
	} // end of 'run' loop

	// #### average over runs and batches ####
	averagedTimeSeriesResults = performanceResultMatrix.getTimePointWiseAverageRunVector();
	averagedOverallResults    = performanceResultMatrix.getOverallAveragePerformanceVector();  // equivalent to line below
	// averagedOverallResults = RunVector.average(averagedTimeSeriesResults);                  // equivalent to line above

	// #### construct operator output ####
	IOObject[]  outputArray = new IOObject[2];
	outputArray[0] = averagedOverallResults;
	outputArray[1] = averagedTimeSeriesResults;

	// setResult(averagedOverallResults.get(0));           // RK/2003/04/30: old
	setResult(averagedOverallResults.getMainCriterion());  // RK/2003/04/30: new
	
	LogService.logMessage("ConceptDriftSimulator '" + getName() + "': complete concept drift simulation", LogService.TASK);

	return outputArray;
    }



    /** returns the maximum of two integer variables. */
    private int  maximumInt (int v1, int v2) {
	if (v1 > v2)  return v1;
	return v2;
    }



    /** scan data stream names from the given string. */
    private String[]  scanStreamNames (String[] streamNames, String streamNamesString) {
	StringTokenizer tokenizer   = new StringTokenizer (streamNamesString);
	int             streamIndex = 0;
	String          outString   = "\nStream names read from configuration file:\n";