org.hipparchus.util

Class KthSelector

java.lang.Object

org.hipparchus.util.KthSelector

All Implemented Interfaces:

Serializable

public class KthSelector
extends Object
implements Serializable

A Simple K^th selector implementation to pick up the K^th ordered element from a work array containing the input numbers.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
KthSelector() Constructor with default median of 3 pivoting strategy.
KthSelector(PivotingStrategy pivotingStrategy) Constructor with specified pivoting strategy

Method Summary

Modifier and Type	Method and Description
PivotingStrategy	getPivotingStrategy() Get the pivoting strategy.
double	select(double[] work, int[] pivotsHeap, int k) Select Kth value in the array.

Methods inherited from class java.lang.Object

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

Constructor Detail

KthSelector

public KthSelector()

Constructor with default median of 3 pivoting strategy.

KthSelector

public KthSelector(PivotingStrategy pivotingStrategy)
            throws NullArgumentException

Constructor with specified pivoting strategy

Parameters:

pivotingStrategy - pivoting strategy to use

Throws:

NullArgumentException - when pivotingStrategy is null

Method Detail

getPivotingStrategy

public PivotingStrategy getPivotingStrategy()

Get the pivoting strategy.

Returns:

pivoting strategy

select

public double select(double[] work,
                     int[] pivotsHeap,
                     int k)

Select K^th value in the array.

Parameters:

work - work array to use to find out the K^th value

pivotsHeap - cached pivots heap that can be used for efficient estimation

k - the index whose value in the array is of interest

Returns:

K^th value