FastElementSequence

public final class FastElementSequence

A sequence recycling the same NdArray instance when iterating its elements

Public Constructors

FastElementSequence ( AbstractNdArray <T, U> ndArray, int dimensionIdx, U element, DataBufferWindow <?> elementWindow)

Public Methods

NdArraySequence <U>
asSlices ()
Returns each element as a new slice.
void
forEachIndexed (BiConsumer<long[], U> consumer)
Iterator<U>

Inherited Methods

Public Constructors

public FastElementSequence ( AbstractNdArray <T, U> ndArray, int dimensionIdx, U element, DataBufferWindow <?> elementWindow)

Public Methods

public NdArraySequence <U> asSlices ()

Returns each element as a new slice.

Unlike conventional Java collections, elements of a NdArraySequence are transient, i.e. new NdArray instances are allocated for each iteration. To improve performance, the same instance can be recycled to view all elements of this sequence, using a DataBufferWindow .

In some cases though, it might be preferable to disable such optimizations to ensure that each element returned is a new slice of the original array. For example, if one or more elements visited must live beyond the scope of the sequence iteration, asSlices() makes sure that all elements returned by the sequence are unique instances.

final List<IntNdArray> vectors = new ArrayList<>();
     IntNdArray matrix = NdArrays.ofInts(Shape.of(6, 6));
     ndArray.elements(0).forEach(e -> vectors::add);  // Not safe, as `e` might always be the same recycled instance
     ndArray.elements(0).asSlices().forEach(e -> vectors::add);  // Safe, each `e` is a distinct NdArray instance
 

Returns
  • a sequence that returns each elements iterated as a new slice

public void forEachIndexed (BiConsumer<long[], U> consumer)

public Iterator<U> iterator ()