org.terrier.utility

Class ArrayUtils

java.lang.Object

org.terrier.utility.ArrayUtils

public class ArrayUtils
extends Object

Handy methods for resizing arrays, and other handy array methods This is a fresh implementation of the capacity methods, without the use of any prelicensed code.

Author:

Ben He, Rodrygo Santos

Field Summary

Fields

Modifier and Type	Field and Description
protected static double	GOLDEN_RATIO the Golden ration (φ).

Constructor Summary

Constructors

Constructor and Description
ArrayUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static int[]	cast(double[] arr) cast double[] to int[]
static double[]	cast(float[] arr) cast float[] to double[]
static double[]	cast(int[] arr) cast int[] to double[]
static byte[]	ensureCapacity(byte[] array, int length) Grow an array to ensure it is the desired length.
static byte[]	ensureCapacity(byte[] array, int length, int preserve) Grow an array to ensure it is the desired length.
static byte[]	grow(byte[] array, int length) Grow an array to ensure it is at least the desired length.
static byte[]	grow(byte[] array, int length, int preserve) Grow an array to ensure it is at least the desired length.
static double[]	grow(double[] array, int length) grow array
static int[]	grow(int[] array, int length) grow array
static short[]	grow(short[] array, int length) grow array
static byte[]	growOrCreate(byte[] arr, int len)
static int[]	growOrCreate(int[] arr, int len)
static int[]	intersection(int[] arr1, int[] arr2) return intersection between two int[]
static int[][]	invert(int[][] input)
static String	join(boolean[] in, String join) Join some strings together.
static String	join(byte[] in, String join) join string
static String	join(double[] in, String join) join string
static String	join(int[] in, String join) Join some strings together.
static String	join(String[] in, char join) Join some strings together.
static String	join(String[] in, String join) Join some strings together.
static String	join(String[] in, String join, int l, int r) Join some strings together.
static int[]	parseCommaDelimitedInts(String src) parse comma delimited int
static String[]	parseCommaDelimitedString(String src) parse comma delimited string
static int[]	parseDelimitedInts(String src, String sep) parse comma delimited int
static String[]	parseDelimitedString(String src, String delim) parse delimited string
static String[]	parseDelimitedString(String src, String[] delims) parse delimited string
static void	reverse(double[] a) Reverse the order of an array of doubles
static void	reverse(int[] a) Reverse the order of an array of ints
static int[]	union(int[] arr1, int[] arr2) union 2 int[]

Methods inherited from class java.lang.Object

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

Field Detail

GOLDEN_RATIO

protected static final double GOLDEN_RATIO

the Golden ration (φ).

See Also:

Constant Field Values

Constructor Detail

ArrayUtils

public ArrayUtils()

Method Detail

invert

public static int[][] invert(int[][] input)

ensureCapacity

public static byte[] ensureCapacity(byte[] array,
                    int length)

Grow an array to ensure it is the desired length.

Parameters:

array - input array

length - ensure array is this length

Returns:

new array with desired length

ensureCapacity

public static byte[] ensureCapacity(byte[] array,
                    int length,
                    int preserve)

Grow an array to ensure it is the desired length. Only copy the first preserve elements from the input array

Parameters:

array - input array

length - new desired length

preserve - amount of old array to copy to new array in case of reallocation

Returns:

new array with desired length

grow

public static byte[] grow(byte[] array,
          int length)

Grow an array to ensure it is at least the desired length. The golden ratio is involved in the new length

Parameters:

array - input array

length - minimuim length of new array

Returns:

new array appropriately sized

growOrCreate

public static int[] growOrCreate(int[] arr,
                 int len)

growOrCreate

public static byte[] growOrCreate(byte[] arr,
                  int len)

reverse

public static void reverse(double[] a)

Reverse the order of an array of doubles

reverse

public static void reverse(int[] a)

Reverse the order of an array of ints

grow

public static byte[] grow(byte[] array,
          int length,
          int preserve)

Grow an array to ensure it is at least the desired length. The golden ratio is involved in the new length. Only copy the first preserve elements from the input array.

Parameters:

array - input array

length - minimuim length of new array

Returns:

new array appropriately sized

join

public static String join(String[] in,
          String join)

Join some strings together.

Parameters:

in - Strings to join

join - Character or String to join by

join

public static String join(String[] in,
          String join,
          int l,
          int r)

Join some strings together.

Parameters:

in -

join -

l -

r -

Returns:

String

join

public static String join(String[] in,
          char join)

Join some strings together.

Parameters:

in - Strings to join

join - Character or String to join by

join

public static String join(int[] in,
          String join)

Join some strings together.

Parameters:

in -

join -

Returns:

String

join

public static String join(boolean[] in,
          String join)

Join some strings together.

Parameters:

in -

join -

Returns:

String

grow

public static int[] grow(int[] array,
         int length)

grow array

Parameters:

array -

length -

Returns:

int[]

grow

public static double[] grow(double[] array,
            int length)

grow array

Parameters:

array -

length -

Returns:

double[]

grow

public static short[] grow(short[] array,
           int length)

grow array

Parameters:

array -

length -

Returns:

short[]

parseCommaDelimitedString

public static String[] parseCommaDelimitedString(String src)

parse comma delimited string

Parameters:

src -

Returns:

String[]

parseDelimitedString

public static String[] parseDelimitedString(String src,
                            String delim)

parse delimited string

Parameters:

src -

delim -

Returns:

String[]

parseDelimitedString

public static String[] parseDelimitedString(String src,
                            String[] delims)

parse delimited string

Parameters:

src -

delims -

Returns:

String[]

parseCommaDelimitedInts

public static int[] parseCommaDelimitedInts(String src)

parse comma delimited int

Parameters:

src -

Returns:

int[]

parseDelimitedInts

public static int[] parseDelimitedInts(String src,
                       String sep)

parse comma delimited int

Parameters:

src -

sep -

Returns:

int[]

join

public static String join(byte[] in,
          String join)

join string

Parameters:

in -

join -

Returns:

String

join

public static String join(double[] in,
          String join)

join string

Parameters:

in -

join -

Returns:

String

cast

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

cast double[] to int[]

Parameters:

arr -

Returns:

int[]

cast

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

cast int[] to double[]

Parameters:

arr -

Returns:

double[]

cast

public static double[] cast(float[] arr)

cast float[] to double[]

Parameters:

arr -

Returns:

double[]

intersection

public static int[] intersection(int[] arr1,
                 int[] arr2)

return intersection between two int[]

Parameters:

arr1 -

arr2 -

Returns:

intersection

union

public static int[] union(int[] arr1,
          int[] arr2)

union 2 int[]

Parameters:

arr1 -

arr2 -

Returns:

int[]