Beispiel #1
0
  @Override
  protected pikater.ontology.messages.Evaluation evaluateCA() {
    Evaluation eval = test();

    pikater.ontology.messages.Evaluation result = new pikater.ontology.messages.Evaluation();
    result.setError_rate((float) eval.errorRate());

    try {
      result.setKappa_statistic((float) eval.kappa());
    } catch (Exception e) {
      result.setKappa_statistic(-1);
    }

    result.setMean_absolute_error((float) eval.meanAbsoluteError());

    try {
      result.setRelative_absolute_error((float) eval.relativeAbsoluteError());
    } catch (Exception e) {
      result.setRelative_absolute_error(-1);
    }

    result.setRoot_mean_squared_error((float) eval.rootMeanSquaredError());
    result.setRoot_relative_squared_error((float) eval.rootRelativeSquaredError());

    return result;
  }
Beispiel #2
0
  /**
   * Evaluates a feature subset by cross validation
   *
   * @param feature_set the subset to be evaluated
   * @param num_atts the number of attributes in the subset
   * @return the estimated accuracy
   * @throws Exception if subset can't be evaluated
   */
  protected double estimatePerformance(BitSet feature_set, int num_atts) throws Exception {

    m_evaluation = new Evaluation(m_theInstances);
    int i;
    int[] fs = new int[num_atts];

    double[] instA = new double[num_atts];
    int classI = m_theInstances.classIndex();

    int index = 0;
    for (i = 0; i < m_numAttributes; i++) {
      if (feature_set.get(i)) {
        fs[index++] = i;
      }
    }

    // create new hash table
    m_entries = new Hashtable((int) (m_theInstances.numInstances() * 1.5));

    // insert instances into the hash table
    for (i = 0; i < m_numInstances; i++) {

      Instance inst = m_theInstances.instance(i);
      for (int j = 0; j < fs.length; j++) {
        if (fs[j] == classI) {
          instA[j] = Double.MAX_VALUE; // missing for the class
        } else if (inst.isMissing(fs[j])) {
          instA[j] = Double.MAX_VALUE;
        } else {
          instA[j] = inst.value(fs[j]);
        }
      }
      insertIntoTable(inst, instA);
    }

    if (m_CVFolds == 1) {

      // calculate leave one out error
      for (i = 0; i < m_numInstances; i++) {
        Instance inst = m_theInstances.instance(i);
        for (int j = 0; j < fs.length; j++) {
          if (fs[j] == classI) {
            instA[j] = Double.MAX_VALUE; // missing for the class
          } else if (inst.isMissing(fs[j])) {
            instA[j] = Double.MAX_VALUE;
          } else {
            instA[j] = inst.value(fs[j]);
          }
        }
        evaluateInstanceLeaveOneOut(inst, instA);
      }
    } else {
      m_theInstances.randomize(m_rr);
      m_theInstances.stratify(m_CVFolds);

      // calculate 10 fold cross validation error
      for (i = 0; i < m_CVFolds; i++) {
        Instances insts = m_theInstances.testCV(m_CVFolds, i);
        evaluateFoldCV(insts, fs);
      }
    }

    switch (m_evaluationMeasure) {
      case EVAL_DEFAULT:
        if (m_classIsNominal) {
          return m_evaluation.pctCorrect();
        }
        return -m_evaluation.rootMeanSquaredError();
      case EVAL_ACCURACY:
        return m_evaluation.pctCorrect();
      case EVAL_RMSE:
        return -m_evaluation.rootMeanSquaredError();
      case EVAL_MAE:
        return -m_evaluation.meanAbsoluteError();
      case EVAL_AUC:
        double[] classPriors = m_evaluation.getClassPriors();
        Utils.normalize(classPriors);
        double weightedAUC = 0;
        for (i = 0; i < m_theInstances.classAttribute().numValues(); i++) {
          double tempAUC = m_evaluation.areaUnderROC(i);
          if (!Utils.isMissingValue(tempAUC)) {
            weightedAUC += (classPriors[i] * tempAUC);
          } else {
            System.err.println("Undefined AUC!!");
          }
        }
        return weightedAUC;
    }
    // shouldn't get here
    return 0.0;
  }
  /**
   * Gets the results for the supplied train and test datasets. Now performs a deep copy of the
   * classifier before it is built and evaluated (just in case the classifier is not initialized
   * properly in buildClassifier()).
   *
   * @param train the training Instances.
   * @param test the testing Instances.
   * @return the results stored in an array. The objects stored in the array may be Strings,
   *     Doubles, or null (for the missing value).
   * @throws Exception if a problem occurs while getting the results
   */
  public Object[] getResult(Instances train, Instances test) throws Exception {

    if (train.classAttribute().type() != Attribute.NUMERIC) {
      throw new Exception("Class attribute is not numeric!");
    }
    if (m_Template == null) {
      throw new Exception("No classifier has been specified");
    }
    ThreadMXBean thMonitor = ManagementFactory.getThreadMXBean();
    boolean canMeasureCPUTime = thMonitor.isThreadCpuTimeSupported();
    if (canMeasureCPUTime && !thMonitor.isThreadCpuTimeEnabled())
      thMonitor.setThreadCpuTimeEnabled(true);

    int addm = (m_AdditionalMeasures != null) ? m_AdditionalMeasures.length : 0;
    Object[] result = new Object[RESULT_SIZE + addm + m_numPluginStatistics];
    long thID = Thread.currentThread().getId();
    long CPUStartTime = -1,
        trainCPUTimeElapsed = -1,
        testCPUTimeElapsed = -1,
        trainTimeStart,
        trainTimeElapsed,
        testTimeStart,
        testTimeElapsed;
    Evaluation eval = new Evaluation(train);
    m_Classifier = AbstractClassifier.makeCopy(m_Template);

    trainTimeStart = System.currentTimeMillis();
    if (canMeasureCPUTime) CPUStartTime = thMonitor.getThreadUserTime(thID);
    m_Classifier.buildClassifier(train);
    if (canMeasureCPUTime) trainCPUTimeElapsed = thMonitor.getThreadUserTime(thID) - CPUStartTime;
    trainTimeElapsed = System.currentTimeMillis() - trainTimeStart;
    testTimeStart = System.currentTimeMillis();
    if (canMeasureCPUTime) CPUStartTime = thMonitor.getThreadUserTime(thID);
    eval.evaluateModel(m_Classifier, test);
    if (canMeasureCPUTime) testCPUTimeElapsed = thMonitor.getThreadUserTime(thID) - CPUStartTime;
    testTimeElapsed = System.currentTimeMillis() - testTimeStart;
    thMonitor = null;

    m_result = eval.toSummaryString();
    // The results stored are all per instance -- can be multiplied by the
    // number of instances to get absolute numbers
    int current = 0;
    result[current++] = new Double(train.numInstances());
    result[current++] = new Double(eval.numInstances());

    result[current++] = new Double(eval.meanAbsoluteError());
    result[current++] = new Double(eval.rootMeanSquaredError());
    result[current++] = new Double(eval.relativeAbsoluteError());
    result[current++] = new Double(eval.rootRelativeSquaredError());
    result[current++] = new Double(eval.correlationCoefficient());

    result[current++] = new Double(eval.SFPriorEntropy());
    result[current++] = new Double(eval.SFSchemeEntropy());
    result[current++] = new Double(eval.SFEntropyGain());
    result[current++] = new Double(eval.SFMeanPriorEntropy());
    result[current++] = new Double(eval.SFMeanSchemeEntropy());
    result[current++] = new Double(eval.SFMeanEntropyGain());

    // Timing stats
    result[current++] = new Double(trainTimeElapsed / 1000.0);
    result[current++] = new Double(testTimeElapsed / 1000.0);
    if (canMeasureCPUTime) {
      result[current++] = new Double((trainCPUTimeElapsed / 1000000.0) / 1000.0);
      result[current++] = new Double((testCPUTimeElapsed / 1000000.0) / 1000.0);
    } else {
      result[current++] = new Double(Utils.missingValue());
      result[current++] = new Double(Utils.missingValue());
    }

    // sizes
    if (m_NoSizeDetermination) {
      result[current++] = -1.0;
      result[current++] = -1.0;
      result[current++] = -1.0;
    } else {
      ByteArrayOutputStream bastream = new ByteArrayOutputStream();
      ObjectOutputStream oostream = new ObjectOutputStream(bastream);
      oostream.writeObject(m_Classifier);
      result[current++] = new Double(bastream.size());
      bastream = new ByteArrayOutputStream();
      oostream = new ObjectOutputStream(bastream);
      oostream.writeObject(train);
      result[current++] = new Double(bastream.size());
      bastream = new ByteArrayOutputStream();
      oostream = new ObjectOutputStream(bastream);
      oostream.writeObject(test);
      result[current++] = new Double(bastream.size());
    }

    // Prediction interval statistics
    result[current++] = new Double(eval.coverageOfTestCasesByPredictedRegions());
    result[current++] = new Double(eval.sizeOfPredictedRegions());

    if (m_Classifier instanceof Summarizable) {
      result[current++] = ((Summarizable) m_Classifier).toSummaryString();
    } else {
      result[current++] = null;
    }

    for (int i = 0; i < addm; i++) {
      if (m_doesProduce[i]) {
        try {
          double dv =
              ((AdditionalMeasureProducer) m_Classifier).getMeasure(m_AdditionalMeasures[i]);
          if (!Utils.isMissingValue(dv)) {
            Double value = new Double(dv);
            result[current++] = value;
          } else {
            result[current++] = null;
          }
        } catch (Exception ex) {
          System.err.println(ex);
        }
      } else {
        result[current++] = null;
      }
    }

    // get the actual metrics from the evaluation object
    List<AbstractEvaluationMetric> metrics = eval.getPluginMetrics();
    if (metrics != null) {
      for (AbstractEvaluationMetric m : metrics) {
        if (m.appliesToNumericClass()) {
          List<String> statNames = m.getStatisticNames();
          for (String s : statNames) {
            result[current++] = new Double(m.getStatistic(s));
          }
        }
      }
    }

    if (current != RESULT_SIZE + addm + m_numPluginStatistics) {
      throw new Error("Results didn't fit RESULT_SIZE");
    }
    return result;
  }