uk.ac.kent.dover.fastGraph

Class Util

java.lang.Object

uk.ac.kent.dover.fastGraph.Util

public class Util
extends java.lang.Object

A class to hold a number of useful methods

Constructor Summary

Constructors

Constructor and Description
Util()

Method Summary

Modifier and Type	Method and Description
static void	addAll(java.util.HashSet<java.lang.Integer> set, int[] array) Adds all items in a primitive array to the given hash set
static void	addAll(java.util.LinkedHashSet<java.lang.Integer> set, int[] array) Adds all items in a primitive array to the given linked hash set
static void	addAll(java.util.LinkedList<java.lang.Integer> list, int[] array) Adds all items in a primitive array to the given linked list
static boolean	areAnyObjectsNull(java.lang.Object... objects) Checks if any of the objects are null
static int	checkForPositiveInteger(java.lang.String input) Checks if a String is a positive integer.
static java.nio.ByteBuffer	cloneByteBuffer(java.nio.ByteBuffer original) Deep copy of ByteBuffer.
static java.util.LinkedList<java.lang.Integer>	convertArray(int[] array) Converts an int[] to a LinkedList of Integer using streams
static void	convertArray(int[] array, java.util.HashSet<java.lang.Integer> set) Converts an int[] to a HashSet of Integer using streams
static void	convertArray(int[] array, java.util.LinkedList<java.lang.Integer> list) Converts an int[] to a LinkedList of Integer using streams
static int[]	convertArrayList(java.util.ArrayList<java.lang.Integer> list) Converts a ArrayList of Integer to an int[] using streams
static int[]	convertHashSet(java.util.HashSet<java.lang.Integer> set) Converts a HashSet of Integer to int[]
static void	convertHashSet(int[] array, java.util.HashSet<java.lang.Integer> set) Converts a HashSet of Integer to a given int[]
static int[]	convertLinkedList(java.util.LinkedList<java.lang.Integer> list) Converts a LinkedList of Integer to an int[] using streams
static void	convertLinkedList(java.util.LinkedList<java.lang.Integer> list, int[] array) Converts a LinkedList of Integer to a given int[] using streams
static <T> void	convertLinkedListObject(java.util.LinkedList<T> list, T[] array) Converts a LinkedList of any given object into an array of that object
static java.lang.String	dateAsString() Returns the current date as yyyyMMdd_HHmm
static <T> T	getFromHashSet(java.util.HashSet<T> set, int number) Gets a specific numbered item from the HashSet given. There is no guarantee this may pick the same entry if run multiple times.
static double	mean(double[] array) Returns the arithmetic mean of an array of doubles
static <T> T	pickRandom(java.util.Random r, java.util.ArrayList<T> list) Picks a random item from a list
static int	pickValidItem(java.util.Random r, int size, java.util.Collection<java.lang.Integer> deleteList) Picks a random int in the range of 0(inc) to size(exc) where the int is not in deleteList
static <T> java.util.ArrayList<T>	randomSelection(java.util.Random r, int number, java.util.ArrayList<T> target) Picks a random sublist of a list.
static double	round(double d, int decimalPlaces) Round to the given number of decimal places.
static int[]	roundAndConvert(double[] toConvert, int places) Rounds and Converts a double[].
static int	roundAndConvert(double toConvert, int places) Rounds and Converts a double.
static int[]	roundAndConvert(int[] res, double[] toConvert, int places) Rounds and Converts a double[].
static int[]	roundArray(double[] arr) Rounds and sorts a double[] to an int[]
static int[][]	roundArray(double[][] arr) Rounds and sorts a double[][] to an int[][]
static double[]	roundArray(double[] arr, int decimalPlaces) Rounds and a double[] to a less precise double[]
static <T extends java.lang.Number> double	standardDeviation(java.util.ArrayList<T> array, double mean) Returns the standard deviation of an array
static double	standardDeviation(double[] array, double mean) Returns the standard deviation of an array
static <T> java.util.List<T>	subList(java.util.ArrayList<T> list, int start, int end) Returns a sublist. A copy of List.sublist() except the end is checked and shortened if too long

Methods inherited from class java.lang.Object

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

Constructor Detail

Util

public Util()

Method Detail

roundArray

public static int[][] roundArray(double[][] arr)

Rounds and sorts a double[][] to an int[][]

Parameters:

arr - a double[][] to be rounded

Returns:

The rounded int[][]

roundArray

public static int[] roundArray(double[] arr)

Rounds and sorts a double[] to an int[]

Parameters:

arr - a double[] to be rounded

Returns:

The rounded int[]

roundArray

public static double[] roundArray(double[] arr,
                                  int decimalPlaces)

Rounds and a double[] to a less precise double[]

Parameters:

arr - a double[] to be rounded

decimalPlaces - the amount of decimal places to round each double in arr

Returns:

The rounded double[]

round

public static double round(double d,
                           int decimalPlaces)

Round to the given number of decimal places.

Parameters:

d - a double to be rounded

decimalPlaces - the number of decimal places

Returns:

The rounded double

roundAndConvert

public static int[] roundAndConvert(double[] toConvert,
                                    int places)

Rounds and Converts a double[]. Multiplies each value by places and converts to an integer

Parameters:

toConvert - The array to convert

places - The number of decimal places to be retained

Returns:

The converted array

roundAndConvert

public static int[] roundAndConvert(int[] res,
                                    double[] toConvert,
                                    int places)

Rounds and Converts a double[]. Multiplies each value by places and converts to an integer

Parameters:

res - The array to be populated

toConvert - The array to convert

places - The number of decimal places to be retained

Returns:

The converted array

roundAndConvert

public static int roundAndConvert(double toConvert,
                                  int places)

Rounds and Converts a double. Multiplies each value by places and converts to an integer

Parameters:

toConvert - The double to convert

places - The number of decimal places to be retained

Returns:

The converted and rounded int

checkForPositiveInteger

public static int checkForPositiveInteger(java.lang.String input)
                                   throws java.lang.NumberFormatException

Checks if a String is a positive integer.

Parameters:

input - The String to be converted

Returns:

The positive integer

Throws:

java.lang.NumberFormatException - If the input is not an integer, or $lt; 0.

convertLinkedListObject

public static <T> void convertLinkedListObject(java.util.LinkedList<T> list,
                                               T[] array)

Converts a LinkedList of any given object into an array of that object

Type Parameters:

T - The type of objects in the list

Parameters:

list - The list to be converted

array - The array to be populated with the new objects

convertLinkedList

public static int[] convertLinkedList(java.util.LinkedList<java.lang.Integer> list)

Converts a LinkedList of Integer to an int[] using streams

Parameters:

list - The linked list to convert

Returns:

The newly created array

convertArrayList

public static int[] convertArrayList(java.util.ArrayList<java.lang.Integer> list)

Converts a ArrayList of Integer to an int[] using streams

Parameters:

list - The ArrayList to convert

Returns:

The newly created array

convertLinkedList

public static void convertLinkedList(java.util.LinkedList<java.lang.Integer> list,
                                     int[] array)

Converts a LinkedList of Integer to a given int[] using streams

Parameters:

list - The linked list to convert

array - The array to be populated

convertArray

public static java.util.LinkedList<java.lang.Integer> convertArray(int[] array)

Converts an int[] to a LinkedList of Integer using streams

Parameters:

array - The array to convert

Returns:

The newly created LinkedList

convertArray

public static void convertArray(int[] array,
                                java.util.LinkedList<java.lang.Integer> list)

Converts an int[] to a LinkedList of Integer using streams

Parameters:

array - The array to convert

list - The newly populated LinkedList

addAll

public static void addAll(java.util.LinkedList<java.lang.Integer> list,
                          int[] array)

Adds all items in a primitive array to the given linked list

Parameters:

list - The list to be added to

array - The array of items to add

addAll

public static void addAll(java.util.LinkedHashSet<java.lang.Integer> set,
                          int[] array)

Adds all items in a primitive array to the given linked hash set

Parameters:

set - The set to be added to

array - The array of items to add

addAll

public static void addAll(java.util.HashSet<java.lang.Integer> set,
                          int[] array)

Adds all items in a primitive array to the given hash set

Parameters:

set - The set to be added to

array - The array of items to add

convertHashSet

public static int[] convertHashSet(java.util.HashSet<java.lang.Integer> set)

Converts a HashSet of Integer to int[]

Parameters:

set - The set to be converted

Returns:

The newly converted array

convertHashSet

public static void convertHashSet(int[] array,
                                  java.util.HashSet<java.lang.Integer> set)

Converts a HashSet of Integer to a given int[]

Parameters:

set - The set to be converted

array - The newly converted array

convertArray

public static void convertArray(int[] array,
                                java.util.HashSet<java.lang.Integer> set)

Converts an int[] to a HashSet of Integer using streams

Parameters:

array - The array to convert

set - The set to store the results in

cloneByteBuffer

public static java.nio.ByteBuffer cloneByteBuffer(java.nio.ByteBuffer original)

Deep copy of ByteBuffer.

Parameters:

original - the ByteBuffer to copy

Returns:

new ByteBuffer with a copy of the content of original.

getFromHashSet

public static <T> T getFromHashSet(java.util.HashSet<T> set,
                                   int number)

Gets a specific numbered item from the HashSet given.
There is no guarantee this may pick the same entry if run multiple times.

Type Parameters:

T - The type of object in the set

Parameters:

set - The Set to look through

number - The item nmber to return

Returns:

The item

subList

public static <T> java.util.List<T> subList(java.util.ArrayList<T> list,
                                            int start,
                                            int end)

Returns a sublist.
A copy of List.sublist() except the end is checked and shortened if too long

Type Parameters:

T - The type of object in the list

Parameters:

list - The list to have a sublist of

start - The start index

end - The end index

Returns:

The sublist

mean

public static double mean(double[] array)

Returns the arithmetic mean of an array of doubles

Parameters:

array - The array

Returns:

The mean

standardDeviation

public static double standardDeviation(double[] array,
                                       double mean)

Returns the standard deviation of an array

Parameters:

array - The array itself

mean - The mean of the array

Returns:

The standard deviation

standardDeviation

public static <T extends java.lang.Number> double standardDeviation(java.util.ArrayList<T> array,
                                                                    double mean)

Returns the standard deviation of an array

Type Parameters:

T - The type of object in the array. Must be a Number.

Parameters:

array - The array itself

mean - The mean of the array

Returns:

The standard deviation

randomSelection

public static <T> java.util.ArrayList<T> randomSelection(java.util.Random r,
                                                         int number,
                                                         java.util.ArrayList<T> target)
                                                  throws FastGraphException

Picks a random sublist of a list. Will not pick duplicates

Type Parameters:

T - The type of object in the list

Parameters:

r - The Random generator

number - The number of items to choose

target - The items to choose from

Returns:

The random sublist

Throws:

FastGraphException - If the list is too small

dateAsString

public static java.lang.String dateAsString()

Returns the current date as yyyyMMdd_HHmm

Returns:

the current date

pickValidItem

public static int pickValidItem(java.util.Random r,
                                int size,
                                java.util.Collection<java.lang.Integer> deleteList)

Picks a random int in the range of 0(inc) to size(exc) where the int is not in deleteList

Parameters:

r - Random number generator

size - The range of items to pick

deleteList - But not in this list

Returns:

The random result

pickRandom

public static <T> T pickRandom(java.util.Random r,
                               java.util.ArrayList<T> list)

Picks a random item from a list

Type Parameters:

T - The type of object in the list

Parameters:

r - Random number generator

list - The list to pick from

Returns:

The random item

areAnyObjectsNull

public static boolean areAnyObjectsNull(java.lang.Object... objects)

Checks if any of the objects are null

Parameters:

objects - The objects to check

Returns:

If any are null