Package weka.core

Class InstanceComparator

java.lang.Object
weka.core.InstanceComparator
All Implemented Interfaces:
Serializable, Comparator<Instance>, RevisionHandler
public class InstanceComparator extends Object implements Comparator<Instance>, Serializable, RevisionHandler
A comparator for the Instance class. it can be used with or without the class label. Missing values are sorted at the beginning.
Can be used as comparator in the sorting and binary search algorithms of Arrays and Collections. Relational values are compared instance by instance with a nested InstanceComparator.
Version:
$Revision: 14911 $
Author:
FracPete (fracpete at cs dot waikato dot ac dot nz)
See Also:

  • Constructor Details

    • InstanceComparator

      public InstanceComparator()
      Initializes the comparator and includes the class in the comparison and all attributes included.

    • InstanceComparator

      public InstanceComparator(boolean includeClass)
      Initializes the comparator with all attributes included.
      Parameters:
      includeClass - whether to include the class in the comparison

    • InstanceComparator

      public InstanceComparator(boolean includeClass, String range, boolean invert)
      Initializes the comparator.
      Parameters:
      includeClass - whether to include the class in the comparison
      range - the attribute range string
      invert - whether to invert the matching sense of the att range

  • Method Details

    • setIncludeClass

      public void setIncludeClass(boolean includeClass)
      Sets whether the class should be included in the comparison.
      Parameters:
      includeClass - true if to include the class in the comparison

    • getIncludeClass

      public boolean getIncludeClass()
      Returns whether the class is included in the comparison.
      Returns:
      true if the class is included

    • setRange

      public void setRange(String value)
      Sets the attribute range to use for comparison.
      Parameters:
      value - the attribute range

    • getRange

      public String getRange()
      Returns the attribute range to use in the comparison.
      Returns:
      the attribute range

    • setInvert

      public void setInvert(boolean invert)
      Sets whether to invert the matching sense of the attribute range.
      Parameters:
      invert - true if to invert the matching sense

    • getInvert

      public boolean getInvert()
      Returns whether the matching sense of the attribute range is inverted.
      Returns:
      true if the matching sense is inverted

    • compare

      public int compare(Instance inst1, Instance inst2)
      compares the two instances, returns -1 if o1 is smaller than o2, 0 if equal and +1 if greater. The method assumes that both instance objects have the same attributes, they don't have to belong to the same dataset.
      Specified by:
      compare in interface Comparator<Instance>
      Parameters:
      inst1 - the first instance to compare
      inst2 - the second instance to compare
      Returns:
      returns -1 if inst1 is smaller than inst2, 0 if equal and +1 if greater

    • getRevision

      public String getRevision()
      Returns the revision string.
      Specified by:
      getRevision in interface RevisionHandler
      Returns:
      the revision

    • main

      public static void main(String[] args) throws Exception
      for testing only. takes an ARFF-filename as first argument to perform some tests.
      Throws:
      Exception