Package org.apache.commons.math4.util

Class MedianOf3PivotingStrategy

java.lang.Object

org.apache.commons.math4.util.MedianOf3PivotingStrategy

All Implemented Interfaces:

java.io.Serializable, PivotingStrategyInterface

public class MedianOf3PivotingStrategy
extends java.lang.Object
implements PivotingStrategyInterface, java.io.Serializable

Classic median of 3 strategy given begin and end indices.

Since:

3.4

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
MedianOf3PivotingStrategy()

Method Summary

Modifier and Type	Method	Description
int	pivotIndex(double[] work, int begin, int end)	Find pivot index of the array so that partition and Kth element selection can be made

Methods inherited from class java.lang.Object

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

Constructor Detail

MedianOf3PivotingStrategy

public MedianOf3PivotingStrategy()

Method Detail

pivotIndex

public int pivotIndex(double[] work,
                      int begin,
                      int end)
               throws MathIllegalArgumentException

Find pivot index of the array so that partition and K^th element selection can be made This in specific makes use of median of 3 pivoting.

Specified by:

pivotIndex in interface PivotingStrategyInterface

Parameters:

work - data array

begin - index of the first element of the slice

end - index after the last element of the slice

Returns:

The index corresponding to a pivot chosen between the first, middle and the last indices of the array slice

Throws:

MathIllegalArgumentException - when indices exceeds range