edu.stanford.nlp.util

Class ArrayUtils

java.lang.Object

edu.stanford.nlp.util.ArrayUtils

public class ArrayUtils
extends java.lang.Object

Static utility methods for operating on arrays. Note: You can also find some methods for printing arrays that are tables in StringUtils. (Search for makeTextTable, etc.)

Author:

Huy Nguyen (htnguyen@cs.stanford.edu), Michel Galley (mgalley@stanford.edu)

Method Summary

Modifier and Type	Method and Description
static <T> java.util.Set<T>	asImmutableSet(T[] a) Return an immutable Set containing the same elements as the specified array.
static java.util.List<java.lang.Integer>	asList(int[] array) needed because Arrays.asList() won't to autoboxing, so if you give it a primitive array you get a singleton list back with just that array as an element.
static double[]	asPrimitiveDoubleArray(java.util.Collection<java.lang.Double> d)
static int[]	asPrimitiveIntArray(java.util.Collection<java.lang.Integer> d)
static <T> java.util.Set<T>	asSet(T[] a) Return a Set containing the same elements as the specified array.
static <T extends java.lang.Comparable<T>> int	compareArrays(T[] first, T[] second) Provides a consistent ordering over arrays.
static int	compareBooleanArrays(boolean[] a1, boolean[] a2)
static <T> T[]	concatenate(T[] first, T[] second) Concatenates two arrays and returns the result
static <T> boolean	contains(T[] a, T o) Returns true iff object o equals (not ==) some element of array a.
static double[]	copy(double[] d)
static double[][]	copy(double[][] d)
static double[][][]	copy(double[][][] d)
static float[]	copy(float[] d)
static float[][]	copy(float[][] d)
static float[][][]	copy(float[][][] d)
static int[]	copy(int[] i)
static int[][]	copy(int[][] i)
static long[]	copy(long[] arr)
static short[]	copy(short[] arr)
static int[]	deltaDecode(byte[] deltaEncoded)
static int[]	deltaDecode(byte[] deltaEncoded, int startIndex, int endIndex)
static java.util.List<java.lang.Integer>	deltaDecodeList(byte[] deltaEncoded)
static java.util.List<java.lang.Integer>	deltaDecodeList(byte[] deltaEncoded, int startIndex, int endIndex)
static byte[]	deltaEncode(int[] orig)
static java.util.List<java.lang.Byte>	deltaEncodeList(int[] orig)
static boolean	equalContents(int[][] xs, int[][] ys) Tests two int[][] arrays for having equal contents.
static boolean	equalContents(int[] xs, int[] ys) tests two int[] arrays for having equal contents
static boolean	equals(boolean[][] xs, boolean[][] ys) Tests two boolean[][] arrays for having equal contents.
static boolean	equals(double[][] xs, double[][] ys) Tests two double[][] arrays for having equal contents.
static void	fill(boolean[][][][] d, boolean val)
static void	fill(boolean[][][] d, boolean val)
static void	fill(boolean[][] d, boolean val)
static void	fill(double[][][][] d, double val)
static void	fill(double[][][] d, double val)
static void	fill(double[][] d, double val)
static <T> T[]	filter(T[] original, java.util.function.Predicate<? super T> filter) Returns an array with only the elements accepted by filter Implementation notes: creates two arrays, calls filter once for each element, does not alter original
static double[]	flatten(double[][] array)
static int[]	gapDecode(byte[] gapEncoded)
static int[]	gapDecode(byte[] gapEncoded, int startIndex, int endIndex)
static java.util.List<java.lang.Integer>	gapDecodeList(byte[] gapEncoded)
static java.util.List<java.lang.Integer>	gapDecodeList(byte[] gapEncoded, int startIndex, int endIndex)
static byte[]	gapEncode(int[] orig)
static java.util.List<java.lang.Byte>	gapEncodeList(int[] orig)
static java.util.List<java.lang.Integer>	getSubListIndex(java.lang.Object[] tofind, java.lang.Object[] tokens)
static java.util.List<java.lang.Integer>	getSubListIndex(java.lang.Object[] tofind, java.lang.Object[] tokens, java.util.function.Predicate<Pair> matchingFunction) If tofind is a part of tokens, it finds the ****starting index***** of tofind in tokens If tofind is not a sub-array of tokens, then it returns null note that tokens sublist should have the exact elements and order as in tofind
static <T> int	indexOf(T[] array, T object) Returns the index of the first occurrence of the specified element in this array, or -1 if this array does not contain the element.
static <T> int	indexOf(T[] array, T object, int startIndex) Returns the index of the first occurrence of the specified element in this array starting at the specified index, or -1 if this array does not contain the element.
static double[]	normalize(double[] ar) Returns a new array which has the numbers in the input array L1-normalized.
static double[]	removeAt(double[] array, int index) Removes the element at the specified index from the array, and returns a new array containing the remaining elements.
static java.lang.Object[]	removeAt(java.lang.Object[] array, int index) Removes the element at the specified index from the array, and returns a new array containing the remaining elements.
static java.lang.Object[]	subArray(java.lang.Object[] arr, int startindexInclusive, int endindexExclusive)
static double[][]	to2D(double[] array, int dim1Size)
static double[][]	to2D(double[] array, int dim1Size, int dim2Size)
static double[]	toDouble(float[] a) Casts to a double array
static double[]	toDouble(int[] array) Casts to a double array.
static double[]	toDoubleArray(java.lang.String[] in)
static char[]	toPrimitive(java.lang.Character[] in)
static char[]	toPrimitive(java.lang.Character[] in, char valueForNull)
static double[]	toPrimitive(java.lang.Double[] in)
static double[]	toPrimitive(java.lang.Double[] in, double valueForNull)
static int[]	toPrimitive(java.lang.Integer[] in)
static int[]	toPrimitive(java.lang.Integer[] in, int valueForNull)
static long[]	toPrimitive(java.lang.Long[] in)
static long[]	toPrimitive(java.lang.Long[] in, long valueForNull)
static short[]	toPrimitive(java.lang.Short[] in)
static short[]	toPrimitive(java.lang.Short[] in, short valueForNull)
static java.lang.String	toString(boolean[][] b)
static java.lang.String	toString(double[][] b)
static java.lang.String	toString(double[] doubles, java.lang.String glue)
static java.lang.String	toString(int[][] a)

Methods inherited from class java.lang.Object

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

Method Detail

gapEncode

public static byte[] gapEncode(int[] orig)

gapEncodeList

public static java.util.List<java.lang.Byte> gapEncodeList(int[] orig)

gapDecode

public static int[] gapDecode(byte[] gapEncoded)

gapDecode

public static int[] gapDecode(byte[] gapEncoded,
                              int startIndex,
                              int endIndex)

gapDecodeList

public static java.util.List<java.lang.Integer> gapDecodeList(byte[] gapEncoded)

gapDecodeList

public static java.util.List<java.lang.Integer> gapDecodeList(byte[] gapEncoded,
                                                              int startIndex,
                                                              int endIndex)

deltaEncode

public static byte[] deltaEncode(int[] orig)

deltaEncodeList

public static java.util.List<java.lang.Byte> deltaEncodeList(int[] orig)

deltaDecode

public static int[] deltaDecode(byte[] deltaEncoded)

deltaDecode

public static int[] deltaDecode(byte[] deltaEncoded,
                                int startIndex,
                                int endIndex)

deltaDecodeList

public static java.util.List<java.lang.Integer> deltaDecodeList(byte[] deltaEncoded)

deltaDecodeList

public static java.util.List<java.lang.Integer> deltaDecodeList(byte[] deltaEncoded,
                                                                int startIndex,
                                                                int endIndex)

flatten

public static double[] flatten(double[][] array)

to2D

public static double[][] to2D(double[] array,
                              int dim1Size)

to2D

public static double[][] to2D(double[] array,
                              int dim1Size,
                              int dim2Size)

removeAt

public static double[] removeAt(double[] array,
                                int index)

Removes the element at the specified index from the array, and returns a new array containing the remaining elements. If index is invalid, returns array unchanged.

removeAt

public static java.lang.Object[] removeAt(java.lang.Object[] array,
                                          int index)

Removes the element at the specified index from the array, and returns a new array containing the remaining elements. If index is invalid, returns array unchanged. Uses reflection to determine the type of the array and returns an array of the appropriate type.

toString

public static java.lang.String toString(int[][] a)

equalContents

public static boolean equalContents(int[][] xs,
                                    int[][] ys)

Tests two int[][] arrays for having equal contents.

Returns:

true iff for each i, equalContents(xs[i],ys[i]) is true

equals

public static boolean equals(double[][] xs,
                             double[][] ys)

Tests two double[][] arrays for having equal contents.

Returns:

true iff for each i, equals(xs[i],ys[i]) is true

equalContents

public static boolean equalContents(int[] xs,
                                    int[] ys)

tests two int[] arrays for having equal contents

Returns:

true iff xs and ys have equal length, and for each i, xs[i]==ys[i]

equals

public static boolean equals(boolean[][] xs,
                             boolean[][] ys)

Tests two boolean[][] arrays for having equal contents.

Returns:

true iff for each i, Arrays.equals(xs[i],ys[i]) is true

contains

public static <T> boolean contains(T[] a,
                                   T o)

Returns true iff object o equals (not ==) some element of array a.

concatenate

public static <T> T[] concatenate(T[] first,
                                  T[] second)

Concatenates two arrays and returns the result

filter

public static <T> T[] filter(T[] original,
                             java.util.function.Predicate<? super T> filter)

Returns an array with only the elements accepted by filter
Implementation notes: creates two arrays, calls filter once for each element, does not alter original

asSet

public static <T> java.util.Set<T> asSet(T[] a)

Return a Set containing the same elements as the specified array.

asImmutableSet

public static <T> java.util.Set<T> asImmutableSet(T[] a)

Return an immutable Set containing the same elements as the specified array. Arrays with 0 or 1 elements are special cased to return the efficient small sets from the Collections class.

fill

public static void fill(double[][] d,
                        double val)

fill

public static void fill(double[][][] d,
                        double val)

fill

public static void fill(double[][][][] d,
                        double val)

fill

public static void fill(boolean[][] d,
                        boolean val)

fill

public static void fill(boolean[][][] d,
                        boolean val)

fill

public static void fill(boolean[][][][] d,
                        boolean val)

toDouble

public static double[] toDouble(float[] a)

Casts to a double array

toDouble

public static double[] toDouble(int[] array)

Casts to a double array.

asList

public static java.util.List<java.lang.Integer> asList(int[] array)

needed because Arrays.asList() won't to autoboxing, so if you give it a primitive array you get a singleton list back with just that array as an element.

asPrimitiveDoubleArray

public static double[] asPrimitiveDoubleArray(java.util.Collection<java.lang.Double> d)

asPrimitiveIntArray

public static int[] asPrimitiveIntArray(java.util.Collection<java.lang.Integer> d)

copy

public static long[] copy(long[] arr)

copy

public static int[] copy(int[] i)

copy

public static int[][] copy(int[][] i)

copy

public static short[] copy(short[] arr)

copy

public static double[] copy(double[] d)

copy

public static double[][] copy(double[][] d)

copy

public static double[][][] copy(double[][][] d)

copy

public static float[] copy(float[] d)

copy

public static float[][] copy(float[][] d)

copy

public static float[][][] copy(float[][][] d)

toString

public static java.lang.String toString(double[][] b)

toString

public static java.lang.String toString(boolean[][] b)

toPrimitive

public static long[] toPrimitive(java.lang.Long[] in)

toPrimitive

public static int[] toPrimitive(java.lang.Integer[] in)

toPrimitive

public static short[] toPrimitive(java.lang.Short[] in)

toPrimitive

public static char[] toPrimitive(java.lang.Character[] in)

toPrimitive

public static double[] toPrimitive(java.lang.Double[] in)

toPrimitive

public static long[] toPrimitive(java.lang.Long[] in,
                                 long valueForNull)

toPrimitive

public static int[] toPrimitive(java.lang.Integer[] in,
                                int valueForNull)

toPrimitive

public static short[] toPrimitive(java.lang.Short[] in,
                                  short valueForNull)

toPrimitive

public static char[] toPrimitive(java.lang.Character[] in,
                                 char valueForNull)

toDoubleArray

public static double[] toDoubleArray(java.lang.String[] in)

toPrimitive

public static double[] toPrimitive(java.lang.Double[] in,
                                   double valueForNull)

compareArrays

public static <T extends java.lang.Comparable<T>> int compareArrays(T[] first,
                                                                    T[] second)

Provides a consistent ordering over arrays. First compares by the first element. If that element is equal, the next element is considered, and so on. This is the array version of CollectionUtils.compareLists(java.util.List<T>, java.util.List<T>) and uses the same logic when the arrays are of different lengths.

indexOf

public static <T> int indexOf(T[] array,
                              T object,
                              int startIndex)

Returns the index of the first occurrence of the specified element in this array starting at the specified index, or -1 if this array does not contain the element.

Parameters:

array - Array to search

object - Object to look for

startIndex - Start index

Returns:

index of the specified element in the array, or -1 if the array does not contain the element

indexOf

public static <T> int indexOf(T[] array,
                              T object)

Returns the index of the first occurrence of the specified element in this array, or -1 if this array does not contain the element.

Parameters:

array - Array to search

object - Object to look for

Returns:

index of the specified element in the array, or -1 if the array does not contain the element

getSubListIndex

public static java.util.List<java.lang.Integer> getSubListIndex(java.lang.Object[] tofind,
                                                                java.lang.Object[] tokens)

getSubListIndex

public static java.util.List<java.lang.Integer> getSubListIndex(java.lang.Object[] tofind,
                                                                java.lang.Object[] tokens,
                                                                java.util.function.Predicate<Pair> matchingFunction)

If tofind is a part of tokens, it finds the ****starting index***** of tofind in tokens If tofind is not a sub-array of tokens, then it returns null note that tokens sublist should have the exact elements and order as in tofind

Parameters:

tofind - array you want to find in tokens

tokens -

matchingFunction - function that takes (tofindtoken, token) pair and returns whether they match

Returns:

starting index of the sublist

normalize

public static double[] normalize(double[] ar)

Returns a new array which has the numbers in the input array L1-normalized.

Parameters:

ar - Input array

Returns:

New array that has L1 normalized form of input array

subArray

public static java.lang.Object[] subArray(java.lang.Object[] arr,
                                          int startindexInclusive,
                                          int endindexExclusive)

compareBooleanArrays

public static int compareBooleanArrays(boolean[] a1,
                                       boolean[] a2)

toString

public static java.lang.String toString(double[] doubles,
                                        java.lang.String glue)