Package org.apache.commons.math4.util

Class CentralPivotingStrategy

java.lang.Object
org.apache.commons.math4.util.CentralPivotingStrategy
All Implemented Interfaces:
java.io.Serializable, PivotingStrategyInterface
public class CentralPivotingStrategy
extends java.lang.Object
implements PivotingStrategyInterface, java.io.Serializable
A mid point strategy based on the average of begin and end indices.
Since:
3.4
See Also:
Serialized Form

  • Constructor Summary

    Constructors 
    Constructor Description
    CentralPivotingStrategy()  

  • 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 Details

  • Method Details

    • pivotIndex

      public int pivotIndex​(double[] work, int begin, int end) throws MathIllegalArgumentException
      Find pivot index of the array so that partition and Kth element selection can be made This in particular picks a average of begin and end indices
      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 simple average of the first and the last element indices of the array slice
      Throws:
      MathIllegalArgumentException - when indices exceeds range