Class AbstractCooFieldTensor<T extends AbstractCooFieldTensor<T,U,V>,U extends AbstractDenseFieldTensor<U,V>,V extends Field<V>>

java.lang.Object

org.flag4j.arrays.backend.AbstractTensor<T,V[],V>

org.flag4j.arrays.backend.semiring_arrays.AbstractCooSemiringTensor<T,U,V>

org.flag4j.arrays.backend.ring_arrays.AbstractCooRingTensor<T,U,V>

org.flag4j.arrays.backend.field_arrays.AbstractCooFieldTensor<T,U,V>

Type Parameters:

T - Type of this sparse COO tensor.

U - Type of dense tensor equivalent to T. This type parameter is required because some operations (e.g. AbstractCooSemiringTensor.tensorDot(AbstractCooSemiringTensor, int[], int[]) between two sparse tensors results in a dense tensor.

V - Type of the Field which the data of this tensor belong to.

All Implemented Interfaces:

Serializable, FieldTensorMixin<T,T,V>, TensorOverField<T,T,V[],V>, RingTensorMixin<T,T,V>, TensorOverRing<T,T,V[],V>, SemiringTensorMixin<T,T,V>, TensorOverSemiring<T,T,V[],V>

Direct Known Subclasses:

CooCTensor, CooFieldTensor

public abstract class AbstractCooFieldTensor<T extends AbstractCooFieldTensor<T,U,V>,U extends AbstractDenseFieldTensor<U,V>,V extends Field<V>>
extends AbstractCooRingTensor<T,U,V>
implements FieldTensorMixin<T,T,V>

Base class for all sparse Field tensors stored in coordinate list (COO) format. The data of this COO tensor are elements of a Field.

The non-zero data and non-zero indices of a COO tensor are mutable but the AbstractTensor.shape and total number of non-zero data is fixed.

Sparse tensors allow for the efficient storage of and ops on tensors that contain many zero values.

COO tensors are optimized for hyper-sparse tensors (i.e. tensors which contain almost all zeros relative to the size of the tensor).

A sparse COO tensor is stored as:

• The full shape of the tensor.
• The non-zero AbstractTensor.data of the tensor. All other data in the tensor are assumed to be zero. Zero value can also explicitly be stored in AbstractTensor.data.

• The AbstractCooSemiringTensor.indices of the non-zero value in the sparse tensor. Many ops assume indices to be sorted in a row-major format (i.e. last index increased fastest) but often this is not explicitly verified.

  The AbstractCooSemiringTensor.indices array has shape (nnz, rank) where AbstractCooSemiringTensor.nnz is the number of non-zero data in this sparse tensor and rank is the tensor rank of the tensor. This means indices[i] is the ND index of data[i].

See Also:

• Serialized Form

Field Summary

Fields inherited from class org.flag4j.arrays.backend.semiring_arrays.AbstractCooSemiringTensor

indices, nnz, sparsity, zeroElement

Fields inherited from class org.flag4j.arrays.backend.AbstractTensor

data, rank, shape

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractCooFieldTensor(Shape shape, V[] entries, int[][] indices)	Creates a tensor with the specified data and shape.

Method Summary

Modifier and Type	Method	Description
CooTensor	abs()	Computes the element-wise absolute value of this tensor.
T	div(T b)	Computes the element-wise quotient between two tensors.
T	H(int... axes)	Computes the conjugate transpose of this tensor.
T	H(int axis1, int axis2)	Computes the conjugate transpose of a tensor by conjugating and exchanging axis1 and axis2.
boolean	isFinite()	Checks if this tensor only contains finite values.
boolean	isInfinite()	Checks if this tensor contains at least one infinite value.
boolean	isNaN()	Checks if this tensor contains at least one NaN value.
T	sqrt()	Computes the element-wise square root of this tensor.

Methods inherited from class org.flag4j.arrays.backend.ring_arrays.AbstractCooRingTensor

sub

Methods inherited from class org.flag4j.arrays.backend.semiring_arrays.AbstractCooSemiringTensor

add, argmax, argmin, coalesce, coalesce, copy, density, dropZeros, elemMult, flatten, flatten, get, getZeroElement, makeLikeDenseTensor, makeLikeTensor, makeLikeTensor, max, min, reshape, set, setZeroElement, sortIndices, sparsity, T, T, T, tensorDot, tensorTr, toDense

Methods inherited from class org.flag4j.arrays.backend.AbstractTensor

getData, getRank, getShape, makeLikeTensor, reshape, sameShape, totalEntries

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.flag4j.arrays.backend.field_arrays.FieldTensorMixin

add, add, addEq, addEq, argmax, argmaxAbs, argmin, argminAbs, conj, div, div, divEq, divEq, isOnes, isZeros, makeEmptyDataArray, max, maxAbs, min, minAbs, mult, mult, multEq, multEq, norm, norm, prod, recip, sub, sub, subEq, subEq, sum

Methods inherited from interface org.flag4j.arrays.backend.ring_arrays.TensorOverRing

H, sub

Methods inherited from interface org.flag4j.arrays.backend.semiring_arrays.TensorOverSemiring

add, elemMult, getData, getRank, getShape, makeLikeTensor, tensorDot, tensorDot, tensorDot, tensorDot, tensorTr, tensorTr

Constructor Details

AbstractCooFieldTensor

protected AbstractCooFieldTensor(Shape shape,
 V[] entries,
 int[][] indices)

Creates a tensor with the specified data and shape.

Parameters:

shape - Shape of this tensor.

entries - Entries of this tensor. If this tensor is dense, this specifies all data within the tensor. If this tensor is sparse, this specifies only the non-zero data of the tensor.

Method Details

abs

public CooTensor abs()

Computes the element-wise absolute value of this tensor.

Specified by:

abs in interface TensorOverRing<T extends AbstractCooFieldTensor<T,U,V>,T extends AbstractCooFieldTensor<T,U,V>,V extends Field<V>[],V extends Field<V>>

Returns:

The element-wise absolute value of this tensor.

H

public T H(int axis1,
 int axis2)

Computes the conjugate transpose of a tensor by conjugating and exchanging axis1 and axis2.

Specified by:

H in interface TensorOverRing<T extends AbstractCooFieldTensor<T,U,V>,T extends AbstractCooFieldTensor<T,U,V>,V extends Field<V>[],V extends Field<V>>

Overrides:

H in class AbstractCooRingTensor<T extends AbstractCooFieldTensor<T,U,V>,U extends AbstractDenseFieldTensor<U,V>,V extends Field<V>>

Parameters:

axis1 - First axis to exchange and conjugate.

axis2 - Second axis to exchange and conjugate.

Returns:

The conjugate transpose of this tensor according to the specified axes.

Throws:

IndexOutOfBoundsException - If either axis1 or axis2 are out of bounds for the rank of this tensor.

See Also:

• TensorOverRing.H()
• H(int...)

H

public T H(int... axes)

Computes the conjugate transpose of this tensor. That is, conjugates and permutes the axes of this tensor so that it matches the permutation specified by axes.

Specified by:

H in interface TensorOverRing<T extends AbstractCooFieldTensor<T,U,V>,T extends AbstractCooFieldTensor<T,U,V>,V extends Field<V>[],V extends Field<V>>

Overrides:

H in class AbstractCooRingTensor<T extends AbstractCooFieldTensor<T,U,V>,U extends AbstractDenseFieldTensor<U,V>,V extends Field<V>>

Parameters:

axes - Permutation of tensor axis. If the tensor has rank N, then this must be an array of length N which is a permutation of {0, 1, 2, ..., N-1}.

Returns:

The conjugate transpose of this tensor with its axes permuted by the axes array.

Throws:

IndexOutOfBoundsException - If any element of axes is out of bounds for the rank of this tensor.

IllegalArgumentException - If axes is not a permutation of {1, 2, 3, ... N-1}.

See Also:

• H(int, int)
• TensorOverRing.H()

div

public T div(T b)

Computes the element-wise quotient between two tensors.

WARNING: This method is not supported for sparse tensors. If called on a sparse tensor, an UnsupportedOperationException will be thrown. Element-wise division is undefined for sparse matrices as it would almost certainly result in a division by zero.

Specified by:

div in interface TensorOverField<T extends AbstractCooFieldTensor<T,U,V>,T extends AbstractCooFieldTensor<T,U,V>,V extends Field<V>[],V extends Field<V>>

Parameters:

b - Second tensor in the element-wise quotient.

Returns:

The element-wise quotient of this tensor with b.

Throws:

UnsupportedOperationException - if this method is ever invoked on a sparse tensor.

sqrt

public T sqrt()

Computes the element-wise square root of this tensor.

Specified by:

sqrt in interface TensorOverField<T extends AbstractCooFieldTensor<T,U,V>,T extends AbstractCooFieldTensor<T,U,V>,V extends Field<V>[],V extends Field<V>>

Returns:

The element-wise square root of this tensor.

isFinite

public boolean isFinite()

Checks if this tensor only contains finite values.

Specified by:

isFinite in interface TensorOverField<T extends AbstractCooFieldTensor<T,U,V>,T extends AbstractCooFieldTensor<T,U,V>,V extends Field<V>[],V extends Field<V>>

Returns:

true if this tensor only contains finite values; false otherwise.

See Also:

• isInfinite()
• isNaN()

isInfinite

public boolean isInfinite()

Checks if this tensor contains at least one infinite value.

Specified by:

isInfinite in interface TensorOverField<T extends AbstractCooFieldTensor<T,U,V>,T extends AbstractCooFieldTensor<T,U,V>,V extends Field<V>[],V extends Field<V>>

Returns:

true if this tensor contains at least one infinite value; false otherwise.

See Also:

• isFinite()
• isNaN()

isNaN

public boolean isNaN()

Checks if this tensor contains at least one NaN value.

Specified by:

isNaN in interface TensorOverField<T extends AbstractCooFieldTensor<T,U,V>,T extends AbstractCooFieldTensor<T,U,V>,V extends Field<V>[],V extends Field<V>>

Returns:

true if this tensor contains at least one NaN value; false otherwise.

See Also:

• isFinite()
• isInfinite()