Package adams.data.instances

Class InstanceComparator

java.lang.Object

adams.data.instances.InstanceComparator

All Implemented Interfaces:

Serializable, Comparator<weka.core.Instance>

public class InstanceComparator
extends Object
implements Serializable, Comparator<weka.core.Instance>

For comparing instance objects. It is assumed that the dataset that the two instance objects belong to are compatible.

Author:

fracpete (fracpete at waikato dot ac dot nz)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean[]	m_Ascending	whether to sort ascending or descending.
protected int[]	m_Indices	the column indices to use in the comparison.

Constructor Summary

Constructors

Constructor	Description
InstanceComparator(int[] indices)	Initializes the comparator.
InstanceComparator(int[] indices, boolean[] ascending)	Initializes the comparator.

Method Summary

Modifier and Type	Method	Description
int	compare(weka.core.Instance o1, weka.core.Instance o2)	Compares its two arguments for order.
boolean[]	getAscending()	Returns whether a column is sorted in ascending or descending order.
int[]	getIndices()	Returns the indices used for sorting.
String	toString()	Returns a short description of the comparator.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Detail

m_Indices

protected int[] m_Indices

the column indices to use in the comparison.

m_Ascending

protected boolean[] m_Ascending

whether to sort ascending or descending.

Constructor Detail

InstanceComparator

public InstanceComparator(int[] indices)

Initializes the comparator. Uses ascending sort order for all columns.

Parameters:

indices - the indices of the columns to compare

InstanceComparator

public InstanceComparator(int[] indices,
                          boolean[] ascending)

Initializes the comparator.

Parameters:

indices - the indices of the columns to compare

ascending - whether to sort ascending or descending, ascending if null

Method Detail

getIndices

public int[] getIndices()

Returns the indices used for sorting.

Returns:

the (0-based) indices

getAscending

public boolean[] getAscending()

Returns whether a column is sorted in ascending or descending order.

Returns:

the sorting order

compare

public int compare(weka.core.Instance o1,
                   weka.core.Instance o2)

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

Specified by:

compare in interface Comparator<weka.core.Instance>

Parameters:

o1 - the first object to be compared.

o2 - the second object to be compared.

Returns:

a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

toString

public String toString()

Returns a short description of the comparator.

Overrides:

toString in class Object

Returns:

the description