org.nd4j.linalg.util

Class ArrayUtil

java.lang.Object

org.nd4j.linalg.util.ArrayUtil

public class ArrayUtil
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
ArrayUtil()

Method Summary

Modifier and Type	Method and Description
static boolean	anyLess(int[] target, int[] test)
static boolean	anyMore(int[] target, int[] test)
static void	assertSquare(double[]... d)
static int[]	calcStrides(int[] shape) Computes the standard packed array strides for a given shape.
static int[]	calcStrides(int[] shape, int startValue) Computes the standard packed array strides for a given shape.
static int[]	calcStridesFortran(int[] shape) Computes the standard packed array strides for a given shape.
static int[]	calcStridesFortran(int[] shape, int startNum) Computes the standard packed array strides for a given shape.
static <E> E[]	combine(E[]... arrs)
static double[]	combine(float[]... ints) Combines a applyTransformToDestination of int arrays in to one flat int array
static int[]	combine(int[]... ints) Combines a applyTransformToDestination of int arrays in to one flat int array
static float[]	combine(java.util.List<float[]> nums) Combines a applyTransformToDestination of int arrays in to one flat int array
static double[]	combineDouble(java.util.List<double[]> nums) Combines a applyTransformToDestination of int arrays in to one flat int array
static float[]	combineFloat(java.util.List<float[]> nums) Combines a applyTransformToDestination of int arrays in to one flat int array
static int[]	consArray(int a, int[] as)
static int[]	copy(int[] copy)
static int	dotProduct(int[] xs, int[] ys)
static double[]	doubleCopyOf(float[] data)
static int[]	empty()
static boolean	equals(float[] data, double[] data2)
static double[]	flatten(double[][] arr)
static int[]	flatten(int[][] arr)
static float[]	floatCopyOf(double[] data)
static boolean	isZero(int[] as)
static int	nonOneStride(int[] arr) For use with row vectors to ensure consistent strides with varying offsets
static int[]	of(int... arr)
static int[]	plus(int[] ints, int mult)
static int	prod(int[] mult)
static int[]	randomPermutation(int size) Credit to mikio braun from jblas Create a random permutation of the numbers 0, ..., size - 1.
static double[]	range(double[] data, int to) Returns a subset of an array from 0 to "to"
static double[]	range(double[] data, int to, int stride) Returns a subset of an array from 0 to "to" using the specified stride
static double[]	range(double[] data, int to, int stride, int numElementsEachStride) Returns a subset of an array from 0 to "to" using the specified stride
static int[]	range(int from, int to) Generate an int array ranging from from to to.
static int[]	range(int from, int to, int increment) Generate an int array ranging from from to to.
static double[]	read(int length, java.io.DataInputStream dis)
static double[]	readDouble(int length, java.io.DataInputStream dis)
static float[]	readFloat(int length, java.io.DataInputStream dis)
static int[]	removeIndex(int[] data, int index) Return a copy of this array with the given index omitted
static java.lang.Integer[]	removeIndex(java.lang.Integer[] data, int index) Returns the array with the item in index removed, if the array is empty it will return the array itself
static int[]	replace(int[] data, int index, int newValue) Return a copy of this array with the given index omitted
static <E> void	reverse(E[] e)
static void	reverse(int[] e) Reverse the passed in array in place
static <E> E[]	reverseCopy(E[] e)
static float[]	reverseCopy(float[] e)
static int[]	reverseCopy(int[] e) Create a backwards copy of the given array
static int[]	times(int[] ints, int mult)
static int[]	times(int[] ints, int[] mult)
static int[]	toArray(java.util.List<java.lang.Integer> list)
static double[]	toArrayDouble(java.util.List<java.lang.Double> list)
static double[][]	toDouble(int[][] arr)
static double[]	toDoubles(int[] ints)
static double[]	toDoubles(int[][] ints)
static float[]	toFloats(int[] ints)
static int[]	toInts(INDArray n)
static INDArray	toNDArray(int[] nums)
static INDArray	toNDArray(int[][] nums)
static int[]	toOutcomeArray(int outcome, int numOutcomes)
static void	write(double[] data, java.io.DataOutputStream dos)
static void	write(float[] data, java.io.DataOutputStream dos)

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayUtil

public ArrayUtil()

Method Detail

randomPermutation

public static int[] randomPermutation(int size)

Credit to mikio braun from jblas Create a random permutation of the numbers 0, ..., size - 1. see Algorithm P, D.E. Knuth: The Art of Computer Programming, Vol. 2, p. 145

toNDArray

public static INDArray toNDArray(int[][] nums)

toNDArray

public static INDArray toNDArray(int[] nums)

toInts

public static int[] toInts(INDArray n)

prod

public static int prod(int[] mult)

equals

public static boolean equals(float[] data,
                             double[] data2)

consArray

public static int[] consArray(int a,
                              int[] as)

isZero

public static boolean isZero(int[] as)

anyMore

public static boolean anyMore(int[] target,
                              int[] test)

anyLess

public static boolean anyLess(int[] target,
                              int[] test)

dotProduct

public static int dotProduct(int[] xs,
                             int[] ys)

empty

public static int[] empty()

of

public static int[] of(int... arr)

copy

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

doubleCopyOf

public static double[] doubleCopyOf(float[] data)

floatCopyOf

public static float[] floatCopyOf(double[] data)

range

public static double[] range(double[] data,
                             int to)

Returns a subset of an array from 0 to "to"

Parameters:

data - the data to getFromOrigin a subset of

to - the end point of the data

Returns:

the subset of the data specified

range

public static double[] range(double[] data,
                             int to,
                             int stride)

Returns a subset of an array from 0 to "to" using the specified stride

Parameters:

data - the data to getFromOrigin a subset of

to - the end point of the data

stride - the stride to go through the array

Returns:

the subset of the data specified

range

public static double[] range(double[] data,
                             int to,
                             int stride,
                             int numElementsEachStride)

Returns a subset of an array from 0 to "to" using the specified stride

Parameters:

data - the data to getFromOrigin a subset of

to - the end point of the data

stride - the stride to go through the array

numElementsEachStride - the number of elements to collect at each stride

Returns:

the subset of the data specified

toArray

public static int[] toArray(java.util.List<java.lang.Integer> list)

toArrayDouble

public static double[] toArrayDouble(java.util.List<java.lang.Double> list)

range

public static int[] range(int from,
                          int to,
                          int increment)

Generate an int array ranging from from to to. if from is > to this method will count backwards

Parameters:

from - the from

to - the end point of the data

increment - the amount to increment by

Returns:

the int array with a length equal to absoluteValue(from - to)

range

public static int[] range(int from,
                          int to)

Generate an int array ranging from from to to. if from is > to this method will count backwards

Parameters:

from - the from

to - the end point of the data

Returns:

the int array with a length equal to absoluteValue(from - to)

toDoubles

public static double[] toDoubles(int[] ints)

toDoubles

public static double[] toDoubles(int[][] ints)

toFloats

public static float[] toFloats(int[] ints)

replace

public static int[] replace(int[] data,
                            int index,
                            int newValue)

Return a copy of this array with the given index omitted

Parameters:

data - the data to copy

index - the index of the item to remove

newValue - the newValue to replace

Returns:

the new array with the omitted item

removeIndex

public static int[] removeIndex(int[] data,
                                int index)

Return a copy of this array with the given index omitted

Parameters:

data - the data to copy

index - the index of the item to remove

Returns:

the new array with the omitted item

removeIndex

public static java.lang.Integer[] removeIndex(java.lang.Integer[] data,
                                              int index)

Returns the array with the item in index removed, if the array is empty it will return the array itself

Parameters:

data - the data to remove data from

index - the index of the item to remove

Returns:

a copy of the array with the removed item, or the array itself if empty

calcStridesFortran

public static int[] calcStridesFortran(int[] shape,
                                       int startNum)

Computes the standard packed array strides for a given shape.

Parameters:

shape - the shape of a matrix:

startNum - the start number for the strides

Returns:

the strides for a matrix of n dimensions

calcStridesFortran

public static int[] calcStridesFortran(int[] shape)

Computes the standard packed array strides for a given shape.

Parameters:

shape - the shape of a matrix:

Returns:

the strides for a matrix of n dimensions

calcStrides

public static int[] calcStrides(int[] shape,
                                int startValue)

Computes the standard packed array strides for a given shape.

Parameters:

shape - the shape of a matrix:

startValue - the startValue for the strides

Returns:

the strides for a matrix of n dimensions

plus

public static int[] plus(int[] ints,
                         int mult)

times

public static int[] times(int[] ints,
                          int mult)

times

public static int[] times(int[] ints,
                          int[] mult)

nonOneStride

public static int nonOneStride(int[] arr)

For use with row vectors to ensure consistent strides with varying offsets

Parameters:

arr - the array to getScalar the stride for

Returns:

the stride

calcStrides

public static int[] calcStrides(int[] shape)

Computes the standard packed array strides for a given shape.

Parameters:

shape - the shape of a matrix:

Returns:

the strides for a matrix of n dimensions

reverseCopy

public static int[] reverseCopy(int[] e)

Create a backwards copy of the given array

Parameters:

e - the array to createComplex a reverse clone of

Returns:

the reversed copy

read

public static double[] read(int length,
                            java.io.DataInputStream dis)
                     throws java.io.IOException

Throws:

java.io.IOException

write

public static void write(double[] data,
                         java.io.DataOutputStream dos)
                  throws java.io.IOException

Throws:

java.io.IOException

readDouble

public static double[] readDouble(int length,
                                  java.io.DataInputStream dis)
                           throws java.io.IOException

Throws:

java.io.IOException

readFloat

public static float[] readFloat(int length,
                                java.io.DataInputStream dis)
                         throws java.io.IOException

Throws:

java.io.IOException

write

public static void write(float[] data,
                         java.io.DataOutputStream dos)
                  throws java.io.IOException

Throws:

java.io.IOException

assertSquare

public static void assertSquare(double[]... d)

reverse

public static void reverse(int[] e)

Reverse the passed in array in place

Parameters:

e - the array to reverse

reverseCopy

public static float[] reverseCopy(float[] e)

reverseCopy

public static <E> E[] reverseCopy(E[] e)

reverse

public static <E> void reverse(E[] e)

flatten

public static int[] flatten(int[][] arr)

flatten

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

toDouble

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

combineFloat

public static float[] combineFloat(java.util.List<float[]> nums)

Combines a applyTransformToDestination of int arrays in to one flat int array

Parameters:

nums - the int arrays to combineDouble

Returns:

one combined int array

combine

public static float[] combine(java.util.List<float[]> nums)

Combines a applyTransformToDestination of int arrays in to one flat int array

Parameters:

nums - the int arrays to combineDouble

Returns:

one combined int array

combineDouble

public static double[] combineDouble(java.util.List<double[]> nums)

Combines a applyTransformToDestination of int arrays in to one flat int array

Parameters:

nums - the int arrays to combineDouble

Returns:

one combined int array

combine

public static double[] combine(float[]... ints)

Combines a applyTransformToDestination of int arrays in to one flat int array

Parameters:

ints - the int arrays to combineDouble

Returns:

one combined int array

combine

public static int[] combine(int[]... ints)

Combines a applyTransformToDestination of int arrays in to one flat int array

Parameters:

ints - the int arrays to combineDouble

Returns:

one combined int array

combine

public static <E> E[] combine(E[]... arrs)

toOutcomeArray

public static int[] toOutcomeArray(int outcome,
                                   int numOutcomes)