org.opensourcephysics.numerics
Class ArrayLib

java.lang.Object
  org.opensourcephysics.numerics.ArrayLib

public abstract class ArrayLib
extends java.lang.Object

Library of supplementary array routines not supported by the java.util.Arrays class.

Author:

jeffrey heer

Field Summary

static int	IndexMax
static int	IndexMin
static int	SORT_THRESHOLD Arrays with lengths beneath this value will be insertion sorted.

Constructor Summary

ArrayLib()

Method Summary

static int	binarySearch(int[] a, int key) Perform a binary search over a sorted array for the given key.
static int	binarySearch(int[] a, int key, int length) Perform a binary search over a sorted range of an array for the given key.
static int	binarySearch(int[] a, int key, int begin, int end) Perform a binary search over a sorted range of an array for the given key.
static int	binarySearch(java.lang.Object[] a, java.lang.Object key) Perform a binary search over a sorted array for the given key.
static int	binarySearch(java.lang.Object[] a, java.lang.Object key, java.util.Comparator<java.lang.Object> cp) Perform a binary search over a sorted array for the given key.
static int	binarySearch(java.lang.Object[] a, java.lang.Object key, java.util.Comparator<java.lang.Object> cp, int length) Perform a binary search over a sorted range of an array for the given key.
static int	binarySearch(java.lang.Object[] a, java.lang.Object key, java.util.Comparator<java.lang.Object> cp, int begin, int end) Perform a binary search over a sorted range of an array for the given key.
static int	binarySearch(java.lang.Object[] a, java.lang.Object key, int length) Perform a binary search over a sorted range of an array for the given key.
static int	binarySearch(java.lang.Object[] a, java.lang.Object key, int begin, int end) Perform a binary search over a sorted range of an array for the given key.
static int	find(int[] a, int key) Linearly search an array for a given key value.
static int	find(int[] a, int key, int length) Linearly search an array range for a given key value.
static int	find(int[] a, int key, int begin, int end) Linearly search an array range for a given key value.
static int	getIndexMax()
static int	getIndexMin()
static int[]	getIntArray(java.lang.String filename) Read in a text file as an array of integers.
static double	max(double[] a) Find the maximum value in an array.
static double	min(double[] a) Find the minimum value in an array.
static double[]	resize(double[] a, int size) Resize the given array as needed to meet a target size.
static float[]	resize(float[] a, int size) Resize the given array as needed to meet a target size.
static int[]	resize(int[] a, int size) Resize the given array as needed to meet a target size.
static java.lang.Object[]	resize(java.lang.Object[] a, int size) Resize the given array as needed to meet a target size.
static void	shuffle(double[] a, int start, int len, java.util.Random r) Randomly permute the contents of a range an array.
static void	shuffle(double[] a, java.util.Random r) Randomly permute the contents of an array.
static void	shuffle(float[] a, int start, int len, java.util.Random r) Randomly permute the contents of a range an array.
static void	shuffle(float[] a, java.util.Random r) Randomly permute the contents of an array.
static void	shuffle(int[] a, int start, int len, java.util.Random r) Randomly permute the contents of a range an array.
static void	shuffle(int[] a, java.util.Random r) Randomly permute the contents of an array.
static void	shuffle(long[] a, int start, int len, java.util.Random r) Randomly permute the contents of a range an array.
static void	shuffle(long[] a, java.util.Random r) Randomly permute the contents of an array.
static void	shuffle(java.lang.Object[] a, int start, int len, java.util.Random r) Randomly permute the contents of a range an array.
static void	shuffle(java.lang.Object[] a, java.util.Random r) Randomly permute the contents of an array.
static void	sort(double[] a, int[] b) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(double[] a, int[] b, int length) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(double[] a, int[] b, int begin, int end) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(float[] a, int[] b) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(float[] a, int[] b, int length) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(float[] a, int[] b, int begin, int end) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(int[] a, double[] b) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(int[] a, double[] b, int length) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(int[] a, double[] b, int begin, int end) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(int[] a, int[] b) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(int[] a, int[] b, int length) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(int[] a, int[] b, int begin, int end) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(int[] a, java.lang.Object[] b, int[] abuf, java.lang.Object[] bbuf, int begin, int end) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(int[] a, java.lang.Object[] b, int begin, int end) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(java.lang.Object[] a, int[] b, java.util.Comparator<java.lang.Object> cmp) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(java.lang.Object[] a, int[] b, int length, java.util.Comparator<java.lang.Object> cmp) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static void	sort(java.lang.Object[] a, int[] b, int begin, int end, java.util.Comparator<java.lang.Object> cmp) Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.
static double	sum(double[] a) Compute the sum of the values in an array.
static double[]	trim(double[] a, int size) Trims an array to be exactly the target a size.
static float[]	trim(float[] a, int size) Trims an array to be exactly the target a size.
static int[]	trim(int[] a, int size) Trims an array to be exactly the target a size.
static java.lang.Object[]	trim(java.lang.Object[] a, int size) Trims an array to be exactly the target a size.

Methods inherited from class java.lang.Object

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

Field Detail

IndexMax

public static int IndexMax

IndexMin

public static int IndexMin

SORT_THRESHOLD

public static final int SORT_THRESHOLD

Arrays with lengths beneath this value will be insertion sorted.

See Also:

Constant Field Values

Constructor Detail

ArrayLib

public ArrayLib()

Method Detail

shuffle

public static final void shuffle(int[] a,
                                 java.util.Random r)

Randomly permute the contents of an array.

Parameters:

a - the array to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(int[] a,
                                 int start,
                                 int len,
                                 java.util.Random r)

Randomly permute the contents of a range an array.

Parameters:

a - the array to shuffle

start - the starting index of the range to shuffle

len - then length of the range to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(long[] a,
                                 java.util.Random r)

Randomly permute the contents of an array.

Parameters:

a - the array to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(long[] a,
                                 int start,
                                 int len,
                                 java.util.Random r)

Randomly permute the contents of a range an array.

Parameters:

a - the array to shuffle

start - the starting index of the range to shuffle

len - then length of the range to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(float[] a,
                                 java.util.Random r)

Randomly permute the contents of an array.

Parameters:

a - the array to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(float[] a,
                                 int start,
                                 int len,
                                 java.util.Random r)

Randomly permute the contents of a range an array.

Parameters:

a - the array to shuffle

start - the starting index of the range to shuffle

len - then length of the range to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(double[] a,
                                 java.util.Random r)

Randomly permute the contents of an array.

Parameters:

a - the array to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(double[] a,
                                 int start,
                                 int len,
                                 java.util.Random r)

Randomly permute the contents of a range an array.

Parameters:

a - the array to shuffle

start - the starting index of the range to shuffle

len - then length of the range to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(java.lang.Object[] a,
                                 java.util.Random r)

Randomly permute the contents of an array.

Parameters:

a - the array to shuffle

r - the source of randomness to use

shuffle

public static final void shuffle(java.lang.Object[] a,
                                 int start,
                                 int len,
                                 java.util.Random r)

Randomly permute the contents of a range an array.

Parameters:

a - the array to shuffle

start - the starting index of the range to shuffle

len - then length of the range to shuffle

r - the source of randomness to use

max

public static final double max(double[] a)

Find the maximum value in an array.

Parameters:

a - the array

indMax - the array minimum index

Returns:

the maximum value in the array

min

public static final double min(double[] a)

Find the minimum value in an array.

Parameters:

a - the array

indMin - the array minimum index

Returns:

the minimum value in the array

getIndexMax

public static final int getIndexMax()

Parameters:

IndexMax - the array minimum index

Returns:

IndexMax

getIndexMin

public static final int getIndexMin()

Parameters:

IndexMin - the array minimum index

Returns:

IndexMin

sum

public static final double sum(double[] a)

Compute the sum of the values in an array.

Parameters:

a - the array

Returns:

the sum of the values in the array

binarySearch

public static final int binarySearch(int[] a,
                                     int key)

Perform a binary search over a sorted array for the given key.

Parameters:

a - the array to search

key - the key to search for

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

binarySearch

public static final int binarySearch(int[] a,
                                     int key,
                                     int length)

Perform a binary search over a sorted range of an array for the given key. The range is assumed to start at index 0.

Parameters:

a - the array to search

key - the key to search for

length - the the length of the range to search over.

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

binarySearch

public static final int binarySearch(int[] a,
                                     int key,
                                     int begin,
                                     int end)

Perform a binary search over a sorted range of an array for the given key.

Parameters:

a - the array to search

key - the key to search for

begin - the starting index of the range

end - the ending index of the range, exclusive

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

binarySearch

public static final int binarySearch(java.lang.Object[] a,
                                     java.lang.Object key)

Perform a binary search over a sorted array for the given key.

Parameters:

a - the array to search

key - the key to search for

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

binarySearch

public static final int binarySearch(java.lang.Object[] a,
                                     java.lang.Object key,
                                     int length)

Perform a binary search over a sorted range of an array for the given key. The range is assumed to start at index 0.

Parameters:

a - the array to search

key - the key to search for

length - the the length of the range to search over.

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

binarySearch

public static final int binarySearch(java.lang.Object[] a,
                                     java.lang.Object key,
                                     int begin,
                                     int end)

Perform a binary search over a sorted range of an array for the given key.

Parameters:

a - the array to search

key - the key to search for

begin - the starting index of the range

end - the ending index of the range, exclusive

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

binarySearch

public static final int binarySearch(java.lang.Object[] a,
                                     java.lang.Object key,
                                     java.util.Comparator<java.lang.Object> cp)

Perform a binary search over a sorted array for the given key.

Parameters:

a - the array to search

key - the key to search for

cp - the comparator to use to compare key values

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

binarySearch

public static final int binarySearch(java.lang.Object[] a,
                                     java.lang.Object key,
                                     java.util.Comparator<java.lang.Object> cp,
                                     int length)

Perform a binary search over a sorted range of an array for the given key. The range is assumed to start at index 0.

Parameters:

a - the array to search

key - the key to search for

cp - the comparator to use to compare key values

length - the the length of the range to search over.

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

binarySearch

public static final int binarySearch(java.lang.Object[] a,
                                     java.lang.Object key,
                                     java.util.Comparator<java.lang.Object> cp,
                                     int begin,
                                     int end)

Perform a binary search over a sorted range of an array for the given key.

Parameters:

a - the array to search

key - the key to search for

cp - the comparator to use to compare key values

begin - the starting index of the range

end - the ending index of the range, exclusive

Returns:

the index of the given key if it exists in the array, otherwise -1 times the index value at the insertion point that would be used if the key were added to the array.

find

public static final int find(int[] a,
                             int key)

Linearly search an array for a given key value.

Parameters:

a - the array to search

key - the key to search for

Returns:

the index of the first occurrence of the key in the array, of -1 if the key is not found.

find

public static final int find(int[] a,
                             int key,
                             int length)

Linearly search an array range for a given key value. Assumes that the range begins at index 0.

Parameters:

a - the array to search

key - the key to search for

length - the length of the range to search over

Returns:

the index of the first occurrence of the key in the array, of -1 if the key is not found.

find

public static final int find(int[] a,
                             int key,
                             int begin,
                             int end)

Linearly search an array range for a given key value.

Parameters:

a - the array to search

key - the key to search for

begin - the starting index of the range

end - the ending index of the range, exclusive

Returns:

the index of the first occurrence of the key in the array, of -1 if the key is not found.

resize

public static final int[] resize(int[] a,
                                 int size)

Resize the given array as needed to meet a target size.

Parameters:

a - the array to potentially resize

size - the minimum size of the target array

Returns:

the resized array, if the original array meets the size requirement, it is simply return, otherwise a new array is allocated and the contents of the original array are copied over.

resize

public static final float[] resize(float[] a,
                                   int size)

Resize the given array as needed to meet a target size.

Parameters:

a - the array to potentially resize

size - the minimum size of the target array

Returns:

the resized array, if the original array meets the size requirement, it is simply return, otherwise a new array is allocated and the contents of the original array are copied over.

resize

public static final double[] resize(double[] a,
                                    int size)

Resize the given array as needed to meet a target size.

Parameters:

a - the array to potentially resize

size - the minimum size of the target array

Returns:

the resized array, if the original array meets the size requirement, it is simply return, otherwise a new array is allocated and the contents of the original array are copied over.

resize

public static final java.lang.Object[] resize(java.lang.Object[] a,
                                              int size)

Resize the given array as needed to meet a target size.

Parameters:

a - the array to potentially resize

size - the minimum size of the target array

Returns:

the resized array, if the original array meets the size requirement, it is simply return, otherwise a new array is allocated and the contents of the original array are copied over.

trim

public static final int[] trim(int[] a,
                               int size)

Trims an array to be exactly the target a size.

Parameters:

a - the array to trim

size - the desired size of the array. This value must be lesser than or equal to the size of the input array.

Returns:

a trimmed array instance

trim

public static final float[] trim(float[] a,
                                 int size)

Trims an array to be exactly the target a size.

Parameters:

a - the array to trim

size - the desired size of the array. This value must be lesser than or equal to the size of the input array.

Returns:

a trimmed array instance

trim

public static final double[] trim(double[] a,
                                  int size)

Trims an array to be exactly the target a size.

Parameters:

a - the array to trim

size - the desired size of the array. This value must be lesser than or equal to the size of the input array.

Returns:

a trimmed array instance

trim

public static final java.lang.Object[] trim(java.lang.Object[] a,
                                            int size)

Trims an array to be exactly the target a size.

Parameters:

a - the array to trim

size - the desired size of the array. This value must be lesser than or equal to the size of the input array.

Returns:

a trimmed array instance

sort

public static final void sort(int[] a,
                              double[] b)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

sort

public static final void sort(int[] a,
                              double[] b,
                              int length)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

length - the array range length to sort over

sort

public static final void sort(int[] a,
                              double[] b,
                              int begin,
                              int end)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

begin - the start index of the range to sort

end - the end index, exclusive, of the range to sort

sort

public static final void sort(int[] a,
                              int[] b)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

sort

public static final void sort(int[] a,
                              int[] b,
                              int length)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

length - the array range length to sort over

sort

public static final void sort(int[] a,
                              int[] b,
                              int begin,
                              int end)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

begin - the start index of the range to sort

end - the end index, exclusive, of the range to sort

sort

public static final void sort(int[] a,
                              java.lang.Object[] b,
                              int begin,
                              int end)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

begin - the start index of the range to sort

end - the end index, exclusive, of the range to sort

sort

public static final void sort(int[] a,
                              java.lang.Object[] b,
                              int[] abuf,
                              java.lang.Object[] bbuf,
                              int begin,
                              int end)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

abuf - a buffer array to perform the sorting without allocating any additional memory

bbuf - a buffer array to perform the sorting without allocating any additional memory

begin - the start index of the range to sort

end - the end index, exclusive, of the range to sort

sort

public static final void sort(double[] a,
                              int[] b)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

sort

public static final void sort(double[] a,
                              int[] b,
                              int length)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

length - the length of the range to be sorted

sort

public static final void sort(double[] a,
                              int[] b,
                              int begin,
                              int end)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

begin - the start index of the range to sort

end - the end index, exclusive, of the range to sort

sort

public static final void sort(float[] a,
                              int[] b)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

sort

public static final void sort(float[] a,
                              int[] b,
                              int length)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

length - the length of the range to be sorted

sort

public static final void sort(float[] a,
                              int[] b,
                              int begin,
                              int end)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

begin - the start index of the range to sort

end - the end index, exclusive, of the range to sort

sort

public static final void sort(java.lang.Object[] a,
                              int[] b,
                              java.util.Comparator<java.lang.Object> cmp)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

cmp - the comparator to use to compare key values

sort

public static final void sort(java.lang.Object[] a,
                              int[] b,
                              int length,
                              java.util.Comparator<java.lang.Object> cmp)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

length - the length of the range to be sorted

cmp - the comparator to use to compare key values

sort

public static final void sort(java.lang.Object[] a,
                              int[] b,
                              int begin,
                              int end,
                              java.util.Comparator<java.lang.Object> cmp)

Sort two arrays simultaneously, using the sort order of the values in the first array to determine the sort order for both arrays.

Parameters:

a - the array to sort by

b - the array to re-arrange based on the sort order of the first array.

begin - the start index of the range to sort

end - the end index, exclusive, of the range to sort

cmp - the comparator to use to compare key values

getIntArray

public static int[] getIntArray(java.lang.String filename)

Read in a text file as an array of integers. Uses the default java StringTokenizer to segment the text file. Additionally, tokens beginning with the '#' character are ignored.

Parameters:

filename - the name of the file to read in

Returns:

an array of integers parsed from the file