Package org.nd4j.linalg.util

Class NDArrayMath

java.lang.Object

org.nd4j.linalg.util.NDArrayMath

public class NDArrayMath
extends Object

Author:

Adam Gibson

Method Summary

Modifier and Type	Method	Description
static long	lengthPerSlice(INDArray arr)	Return the length of a slice
static long	lengthPerSlice(INDArray arr, int... dimension)	The number of elements in a slice along a set of dimensions
static int	mapIndexOntoTensor(int index, INDArray arr, int... rank)	This maps an index of a vector on to a vector in the matrix that can be used for indexing in to a tensor
static long	mapIndexOntoVector(int index, INDArray arr)	This maps an index of a vector on to a vector in the matrix that can be used for indexing in to a tensor
static long	matricesPerSlice(INDArray arr)	The number of vectors in each slice of an ndarray.
static long	numVectors(INDArray arr)	Return the number of vectors for an array the number of vectors for an array
static long	offsetForSlice(INDArray arr, int slice)	Compute the offset for a given slice
static long	sliceOffsetForTensor(int index, INDArray arr, int[] tensorShape)	calculates the offset for a tensor
static long	sliceOffsetForTensor(int index, INDArray arr, long[] tensorShape)
static long	tensorsPerSlice(INDArray arr, int[] tensorShape)	Computes the tensors per slice given a tensor shape and array
static long	vectorsPerSlice(INDArray arr)	The number of vectors in each slice of an ndarray.
static long	vectorsPerSlice(INDArray arr, int... rank)	The number of vectors in each slice of an ndarray.

Methods inherited from class java.lang.Object

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

Method Detail

offsetForSlice

public static long offsetForSlice(INDArray arr,
                                  int slice)

Compute the offset for a given slice

Parameters:

arr - the array to compute the offset frm

slice - the slice to compute the offset for

Returns:

the offset for a given slice

lengthPerSlice

public static long lengthPerSlice(INDArray arr,
                                  int... dimension)

The number of elements in a slice along a set of dimensions

Parameters:

arr - the array to calculate the length per slice for

dimension - the dimensions to do the calculations along

Returns:

the number of elements in a slice along arbitrary dimensions

lengthPerSlice

public static long lengthPerSlice(INDArray arr)

Return the length of a slice

Parameters:

arr - the array to get the length of a slice for

Returns:

the number of elements per slice in an array

numVectors

public static long numVectors(INDArray arr)

Return the number of vectors for an array the number of vectors for an array

Parameters:

arr - the array to calculate the number of vectors for

Returns:

the number of vectors for the given array

vectorsPerSlice

public static long vectorsPerSlice(INDArray arr)

The number of vectors in each slice of an ndarray.

Parameters:

arr - the array to get the number of vectors per slice for

Returns:

the number of vectors per slice

tensorsPerSlice

public static long tensorsPerSlice(INDArray arr,
                                   int[] tensorShape)

Computes the tensors per slice given a tensor shape and array

Parameters:

arr - the array to get the tensors per slice for

tensorShape - the desired tensor shape

Returns:

the tensors per slice of an ndarray

matricesPerSlice

public static long matricesPerSlice(INDArray arr)

The number of vectors in each slice of an ndarray.

Parameters:

arr - the array to get the number of vectors per slice for

Returns:

the number of vectors per slice

vectorsPerSlice

public static long vectorsPerSlice(INDArray arr,
                                   int... rank)

The number of vectors in each slice of an ndarray.

Parameters:

arr - the array to get the number of vectors per slice for

rank - the dimensions to get the number of vectors per slice for

Returns:

the number of vectors per slice

sliceOffsetForTensor

public static long sliceOffsetForTensor(int index,
                                        INDArray arr,
                                        int[] tensorShape)

calculates the offset for a tensor

Parameters:

index -

arr -

tensorShape -

Returns:

sliceOffsetForTensor

public static long sliceOffsetForTensor(int index,
                                        INDArray arr,
                                        long[] tensorShape)

mapIndexOntoTensor

public static int mapIndexOntoTensor(int index,
                                     INDArray arr,
                                     int... rank)

This maps an index of a vector on to a vector in the matrix that can be used for indexing in to a tensor

Parameters:

index - the index to map

arr - the array to use for indexing

rank - the dimensions to compute a slice for

Returns:

the mapped index

mapIndexOntoVector

public static long mapIndexOntoVector(int index,
                                      INDArray arr)

This maps an index of a vector on to a vector in the matrix that can be used for indexing in to a tensor

Parameters:

index - the index to map

arr - the array to use for indexing

Returns:

the mapped index