org.nd4j.linalg.indexing

Class Indices

java.lang.Object

org.nd4j.linalg.indexing.Indices

public class Indices
extends java.lang.Object

Indexing util.

Constructor Summary

Constructors

Constructor and Description
Indices()

Method Summary

Modifier and Type	Method and Description
static NDArrayIndex[]	adjustIndices(int[] originalShape, NDArrayIndex... indexes) Prunes indices of greater length than the shape and fills in missing indices if there are any
static NDArrayIndex[]	fillIn(int[] shape, NDArrayIndex... indexes) Fill in the missing indices to be the same length as the original shape.
static boolean	isContiguous(int[] indices) Returns whether the indices are contiguous by one or not
static boolean	isContiguous(int[] indices, int diff) Returns whether indices are contiguous by a certain amount or not
static boolean	isContiguous(int diff, NDArrayIndex... indexes) Returns whether indices are contiguous by a certain amount or not
static boolean	isContiguous(NDArrayIndex... indexes) Returns whether the indices are contiguous by one or not
static int[]	offsets(NDArrayIndex... indices) The offsets (begin index) for each index
static int[]	shape(int[] shape, NDArrayIndex... indices) Calculate the shape for the given set of indices.
static int[]	shape(NDArrayIndex... indices) Calculate the shape for the given set of indices.
static int[]	strides(char ordering, NDArrayIndex... indexes) Calculate the strides based on the given indices

Methods inherited from class java.lang.Object

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

Constructor Detail

Indices

public Indices()

Method Detail

offsets

public static int[] offsets(NDArrayIndex... indices)

The offsets (begin index) for each index

Parameters:

indices - the indices

Returns:

the offsets for the given set of indices

fillIn

public static NDArrayIndex[] fillIn(int[] shape,
                                    NDArrayIndex... indexes)

Fill in the missing indices to be the same length as the original shape. Think of this as what fills in the indices for numpy or matlab: Given a which is (4,3,2) in numpy: a[1:3] is filled in by the rest to give back the full slice This algorithm fills in that delta

Parameters:

shape - the original shape

indexes - the indexes to start from

Returns:

the filled in indices

adjustIndices

public static NDArrayIndex[] adjustIndices(int[] originalShape,
                                           NDArrayIndex... indexes)

Prunes indices of greater length than the shape and fills in missing indices if there are any

Parameters:

originalShape - the original shape to adjust to

indexes - the indexes to adjust

Returns:

the adjusted indices

strides

public static int[] strides(char ordering,
                            NDArrayIndex... indexes)

Calculate the strides based on the given indices

Parameters:

ordering - the ordering to calculate strides for

indexes - the indices to calculate stride for

Returns:

the strides for the given indices

shape

public static int[] shape(NDArrayIndex... indices)

Calculate the shape for the given set of indices. The shape is defined as (for each dimension) the difference between the end index + 1 and the begin index

Parameters:

indices - the indices to calculate the shape for

Returns:

the shape for the given indices

isContiguous

public static boolean isContiguous(NDArrayIndex... indexes)

Returns whether the indices are contiguous by one or not

Parameters:

indexes - the indices to test

Returns:

whether the indices are contiguous by one or not

isContiguous

public static boolean isContiguous(int diff,
                                   NDArrayIndex... indexes)

Returns whether indices are contiguous by a certain amount or not

Parameters:

indexes - the indices to test

diff - the difference considered to be contiguous

Returns:

whether the given indices are contiguous or not

isContiguous

public static boolean isContiguous(int[] indices)

Returns whether the indices are contiguous by one or not

Parameters:

indices - the indices to test

Returns:

whether the indices are contiguous by one or not

isContiguous

public static boolean isContiguous(int[] indices,
                                   int diff)

Returns whether indices are contiguous by a certain amount or not

Parameters:

indices - the indices to test

diff - the difference considered to be contiguous

Returns:

whether the given indices are contiguous or not

shape

public static int[] shape(int[] shape,
                          NDArrayIndex... indices)

Calculate the shape for the given set of indices. The shape is defined as (for each dimension) the difference between the end index + 1 and the begin index If specified, this will check for whether any of the indices are >= to end - 1 and if so, prune it down

Parameters:

shape - the original shape

indices - the indices to calculate the shape for

Returns:

the shape for the given indices