Class KthSelector

java.lang.Object
org.apache.commons.math3.util.KthSelector
All Implemented Interfaces:
Serializable

public class KthSelector extends Object implements Serializable
A Simple Kth selector implementation to pick up the Kth ordered element from a work array containing the input numbers.
Since:
3.4
See Also:
  • Field Details

  • Constructor Details

  • Method Details

    • getPivotingStrategy

      public PivotingStrategyInterface getPivotingStrategy()
      Get the pivotin strategy.
      Returns:
      pivoting strategy
    • select

      public double select(double[] work, int[] pivotsHeap, int k)
      Select Kth value in the array.
      Parameters:
      work - work array to use to find out the Kth value
      pivotsHeap - cached pivots heap that can be used for efficient estimation
      k - the index whose value in the array is of interest
      Returns:
      Kth value
    • partition

      private int partition(double[] work, int begin, int end, int pivot)
      Partition an array slice around a pivot.Partitioning exchanges array elements such that all elements smaller than pivot are before it and all elements larger than pivot are after it.
      Parameters:
      work - work array
      begin - index of the first element of the slice of work array
      end - index after the last element of the slice of work array
      pivot - initial index of the pivot
      Returns:
      index of the pivot after partition