本文整理了Java中weka.core.Utils.missingValue()方法的一些代码示例，展示了Utils.missingValue()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Utils.missingValue()方法的具体详情如下：
包路径：weka.core.Utils
类名称：Utils
方法名：missingValue

Utils.missingValue介绍

[英]Returns the value used to code a missing value. Note that equality tests on this value will always return false, so use isMissingValue(double val) for testing..
[中]返回用于编码缺失值的值。请注意，对该值的相等性测试将始终返回false，因此使用isMissingValue（double val）进行测试。。

代码示例

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

/**
 * Constructor of an instance that sets weight to one, all values to be
 * missing, and the reference to the dataset to null. (ie. the instance
 * doesn't have access to information about the attribute types)
 * 
 * @param numAttributes the size of the instance
 */
// @ requires numAttributes > 0; // Or maybe == 0 is okay too?
// @ ensures m_Dataset == null;
public DenseInstance(int numAttributes) {
 m_AttValues = new double[numAttributes];
 for (int i = 0; i < m_AttValues.length; i++) {
  m_AttValues[i] = Utils.missingValue();
 }
 m_Weight = 1;
 m_Dataset = null;
}

代码示例来源：origin: Waikato/weka-trunk

/**
 * Constructor of an instance that sets weight to one, all values to be
 * missing, and the reference to the dataset to null. (ie. the instance
 * doesn't have access to information about the attribute types)
 * 
 * @param numAttributes the size of the instance
 */
public SparseInstance(int numAttributes) {
 m_AttValues = new double[numAttributes];
 m_NumAttributes = numAttributes;
 m_Indices = new int[numAttributes];
 for (int i = 0; i < m_AttValues.length; i++) {
  m_AttValues[i] = Utils.missingValue();
  m_Indices[i] = i;
 }
 m_Weight = 1;
 m_Dataset = null;
}

代码示例来源：origin: Waikato/weka-trunk

/**
 * Constructor of an instance that sets weight to one, all values to be
 * missing, and the reference to the dataset to null. (ie. the instance
 * doesn't have access to information about the attribute types)
 * 
 * @param numAttributes the size of the instance
 */
// @ requires numAttributes > 0; // Or maybe == 0 is okay too?
// @ ensures m_Dataset == null;
public DenseInstance(int numAttributes) {
 m_AttValues = new double[numAttributes];
 for (int i = 0; i < m_AttValues.length; i++) {
  m_AttValues[i] = Utils.missingValue();
 }
 m_Weight = 1;
 m_Dataset = null;
}

代码示例来源：origin: nz.ac.waikato.cms.weka/distributedWekaBase

/**
 * Get the count for a given label
 * 
 * @param label the label to get the count for
 * @return the count or missing value if the label is unknown
 */
public double getCount(String label) {
 NominalStats.Count c = m_counts.get(label);
 if (c == null) {
  return Utils.missingValue();
 }
 return c.m_count;
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

/**
 * Inserts an attribute at the given position (0 to numAttributes()) and sets
 * its value to be missing.
 * 
 * @param position the attribute's position
 */
@Override
protected void forceInsertAttributeAt(int position) {
 double[] newValues = new double[m_AttValues.length + 1];
 System.arraycopy(m_AttValues, 0, newValues, 0, position);
 newValues[position] = Utils.missingValue();
 System.arraycopy(m_AttValues, position, newValues, position + 1,
  m_AttValues.length - position);
 m_AttValues = newValues;
}

代码示例来源：origin: Waikato/weka-trunk

/**
 * Inserts an attribute at the given position (0 to numAttributes()) and sets
 * its value to be missing.
 * 
 * @param position the attribute's position
 */
@Override
protected void forceInsertAttributeAt(int position) {
 double[] newValues = new double[m_AttValues.length + 1];
 System.arraycopy(m_AttValues, 0, newValues, 0, position);
 newValues[position] = Utils.missingValue();
 System.arraycopy(m_AttValues, position, newValues, position + 1,
  m_AttValues.length - position);
 m_AttValues = newValues;
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

/**
 * Sets a specific value to be "missing". Performs a deep copy of the vector
 * of attribute values before the value is set to be missing.
 * 
 * @param attIndex the attribute's index
 */
@Override
public final void setMissing(int attIndex) {
 setValue(attIndex, Utils.missingValue());
}

代码示例来源：origin: Waikato/weka-trunk

/**
 * Sets a specific value to be "missing". Performs a deep copy of the vector
 * of attribute values before the value is set to be missing.
 * 
 * @param attIndex the attribute's index
 */
@Override
public final void setMissing(int attIndex) {
 setValue(attIndex, Utils.missingValue());
}

代码示例来源：origin: nz.ac.waikato.cms.weka/simpleEducationalLearningSchemes

/**
 * Classifies a given instance.
 *
 * @param inst the instance to be classified
 * @return the classification
 */
public double classifyInstance(Instance inst) {
 int result = m_rules.resultRules(inst);
 if (result == -1) {
  return Utils.missingValue();
 } else {
  return (double)result;
 }
}

代码示例来源：origin: nz.ac.waikato.cms.weka/distributedWekaBase

/**
 * Constructs a new NumericStats
 * 
 * @param attributeName the name of the attribute that these statistics are
 *          for
 */
public NumericStats(String attributeName) {
 super(attributeName);
 m_stats[ArffSummaryNumericMetric.MIN.ordinal()] = Utils.missingValue();
 m_stats[ArffSummaryNumericMetric.MAX.ordinal()] = Utils.missingValue();
 m_stats[ArffSummaryNumericMetric.FIRSTQUARTILE.ordinal()] =
  Utils.missingValue();
 m_stats[ArffSummaryNumericMetric.MEDIAN.ordinal()] = Utils.missingValue();
 m_stats[ArffSummaryNumericMetric.THIRDQUARTILE.ordinal()] =
  Utils.missingValue();
}

代码示例来源：origin: Waikato/weka-trunk

/**
 * Get the value of the attribute as a number or Utils.missingValue() if the
 * attribute is not numeric.
 * 
 * @return the value of the attribute as a number
 */
public double getNumericValue() {
 if (getResolvedType().toLowerCase().startsWith("numeric")) {
  return Double.parseDouble(getResolvedValue());
 }
 return Utils.missingValue(); // not a numeric attribute
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

/**
 * Get the value of the attribute as a number or Utils.missingValue() if the
 * attribute is not numeric.
 * 
 * @return the value of the attribute as a number
 */
public double getNumericValue() {
 if (getResolvedType().toLowerCase().startsWith("numeric")) {
  return Double.parseDouble(getResolvedValue());
 }
 return Utils.missingValue(); // not a numeric attribute
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

/**
 * Evaluate on the basis of the no true child strategy.
 * 
 * @param classAtt the class attribute.
 * @param preds an array to hold the predicted probabilities.
 * @throws Exception if something goes wrong.
 */
protected void doNoTrueChild(Attribute classAtt, double[] preds)
 throws Exception {
 if (TreeModel.this.m_noTrueChildStrategy == NoTrueChildStrategy.RETURNNULLPREDICTION) {
  for (int i = 0; i < classAtt.numValues(); i++) {
   preds[i] = Utils.missingValue();
  }
 } else {
  // return the predictions at this node
  doLeaf(classAtt, preds);
 }
}

代码示例来源：origin: Waikato/weka-trunk

@Override
 public double evaluate() {
  if (isMissing()) {
   missingAccessed = true;
   return Utils.missingValue();
  }
  return instance.value(getIndex());
 }
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

@Override
 public double evaluate() {
  if (isMissing()) {
   missingAccessed = true;
   return Utils.missingValue();
  }
  return instance.value(getIndex());
 }
}

代码示例来源：origin: nz.ac.waikato.cms.weka/distributedWekaBase

/**
 * Update with a new value
 * 
 * @param value the string value to update with
 * @param weight the weight for the update
 */
public void update(String value, double weight) {
 if (DistributedJobConfig.isEmpty(value)) {
  m_missingCount += weight;
  m_stringLengthStats.update(Utils.missingValue(), weight, false, false);
  m_wordStats.update(Utils.missingValue(), weight, false, false);
 } else {
  m_stringLengthStats.update(value.length(), weight, false, false);
  m_tokenizer.tokenize(value);
  m_wordStats.update(m_tokenizer.countTokens(), weight, false, false);
 }
}

代码示例来源：origin: nz.ac.waikato.cms.weka/weka-stable

/**
 * Returns the area under precision-recall curve (AUPRC) for those predictions
 * that have been collected in the evaluateClassifier(Classifier, Instances)
 * method. Returns Utils.missingValue() if the area is not available.
 *
 * @param classIndex the index of the class to consider as "positive"
 * @return the area under the precision-recall curve or not a number
 */
public double areaUnderPRC(int classIndex) {
 // Check if any predictions have been collected
 if (m_Predictions == null) {
  return Utils.missingValue();
 } else {
  ThresholdCurve tc = new ThresholdCurve();
  Instances result = tc.getCurve(m_Predictions, classIndex);
  return ThresholdCurve.getPRCArea(result);
 }
}

代码示例来源：origin: nz.ac.waikato.cms.weka/distributedWekaBase

@Override
public double valueFromAttribute(Attribute att) {
 if (THIRDQUARTILE.ordinal() > att.numValues() - 1) {
  return Utils.missingValue();
 }
 String value = att.value(THIRDQUARTILE.ordinal());
 return toValue(value, toString());
}

代码示例来源：origin: nz.ac.waikato.cms.weka/distributedWekaBase

@Override
public double valueFromAttribute(Attribute att) {
 if (FIRSTQUARTILE.ordinal() > att.numValues() - 1) {
  return Utils.missingValue();
 }
 String value = att.value(FIRSTQUARTILE.ordinal());
 return toValue(value, toString());
}

代码示例来源：origin: nz.ac.waikato.cms.weka/distributedWekaBase

@Override
public double valueFromAttribute(Attribute att) {
 if (MEDIAN.ordinal() > att.numValues() - 1) {
  return Utils.missingValue();
 }
 String value = att.value(MEDIAN.ordinal());
 return toValue(value, toString());
}