RandomPivotingStrategy

java.lang.Object
- org.apache.commons.math3.util.RandomPivotingStrategy

All Implemented Interfaces:

java.io.Serializable, PivotingStrategyInterface
```
public class RandomPivotingStrategy
extends java.lang.Object
implements PivotingStrategyInterface, java.io.Serializable
```
A strategy of selecting random index between begin and end indices.

Since:

3.4

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type Field Description

private RandomGenerator random
Random generator to use for selecting pivot.

private static long serialVersionUID
Serializable UID.

Constructor Summary

Constructors
Constructor Description

RandomPivotingStrategy(RandomGenerator random)
Simple constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`pivotIndex(double[] work, int begin, int end)`	Find pivot index of the array so that partition and K^th element selection can be made

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - serialVersionUID
```
private static final long serialVersionUID
```
    Serializable UID.
    
    See Also:
    
    Constant Field Values
  - random
```
private final RandomGenerator random
```
    Random generator to use for selecting pivot.
- Constructor Detail
  - RandomPivotingStrategy
```
public RandomPivotingStrategy(RandomGenerator random)
```
    Simple constructor.
    
    Parameters:
    
    random - random generator to use for selecting pivot
- 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 A uniform random pivot selection between 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 random uniformly selected value between first and the last indices of the array slice
    
    Throws:
    
    MathIllegalArgumentException - when indices exceeds range