jsat.utils

Class QuickSort

java.lang.Object

jsat.utils.QuickSort

public class QuickSort
extends Object

Provides implementations of quicksort. This is for use to obtain explicitly desired behavior, as well as aovid overhead by explicitly allowing extra Lists when sorting that are swapped when the array/list being sorted is swapped.

This class exist solely for performance reasons.

Author:

Edward Raff

Method Summary

Modifier and Type	Method and Description
static void	insertionSort(double[] x, int start, int end)
static void	sort(double[] x, int start, int end) Performs sorting based on the double values natural comparator.
static void	sort(double[] x, int start, int end, Collection<List<?>> paired) Performs sorting based on the double values natural comparator.
static void	sort(float[] x, int start, int end, Collection<List<?>> paired) Performs sorting based on the double values natural comparator.
static void	swap(double[] array, int i, int j)
static void	swap(double[] array, int i, int j, Collection<List<?>> paired)
static void	swap(float[] array, int i, int j)
static void	swap(float[] array, int i, int j, Collection<List<?>> paired)
static void	swapC(double[] array, int i, int j) Conditional swap, only swaps the values if array[i] > array[j]
protected static void	vecswap(double[] x, int a, int b, int n)
protected static void	vecswap(float[] x, int a, int b, int n)

Methods inherited from class java.lang.Object

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

Method Detail

vecswap

protected static void vecswap(double[] x,
                              int a,
                              int b,
                              int n)

vecswap

protected static void vecswap(float[] x,
                              int a,
                              int b,
                              int n)

swap

public static void swap(double[] array,
                        int i,
                        int j)

swap

public static void swap(float[] array,
                        int i,
                        int j)

swapC

public static void swapC(double[] array,
                         int i,
                         int j)

Conditional swap, only swaps the values if array[i] > array[j]

Parameters:

array - the array to potentially swap values in

i - the 1st index

j - the 2nd index

swap

public static void swap(double[] array,
                        int i,
                        int j,
                        Collection<List<?>> paired)

Parameters:

array - the array to swap values in

i - the 1st index

j - the 2nd index

paired - a collection of lists, every list will have its indices swapped as well

swap

public static void swap(float[] array,
                        int i,
                        int j,
                        Collection<List<?>> paired)

Parameters:

array - the array to swap values in

i - the 1st index

j - the 2nd index

paired - a collection of lists, every list will have its indices swapped as well

sort

public static void sort(double[] x,
                        int start,
                        int end)

Performs sorting based on the double values natural comparator. Double.NaN values will not be handled appropriately.

Parameters:

x - the array to sort

start - the starting index (inclusive) to sort

end - the ending index (exclusive) to sort

insertionSort

public static void insertionSort(double[] x,
                                 int start,
                                 int end)

Parameters:

x -

start - inclusive

end - exclusive

sort

public static void sort(double[] x,
                        int start,
                        int end,
                        Collection<List<?>> paired)

Performs sorting based on the double values natural comparator. Double.NaN values will not be handled appropriately.

Parameters:

x - the array to sort

start - the starting index (inclusive) to sort

end - the ending index (exclusive) to sort

paired - a collection of lists, every list will have its indices swapped as well

sort

public static void sort(float[] x,
                        int start,
                        int end,
                        Collection<List<?>> paired)

Performs sorting based on the double values natural comparator. Double.NaN values will not be handled appropriately.

Parameters:

x - the array to sort

start - the starting index (inclusive) to sort

end - the ending index (exclusive) to sort

paired - a collection of lists, every list will have its indices swapped as well