org.tensorics.core.tensor

Class ImmutableTensor<V>

java.lang.Object

org.tensorics.core.tensor.AbstractTensor<V>

org.tensorics.core.tensor.ImmutableTensor<V>

Type Parameters:

V - type of values in Tensor.

All Implemented Interfaces:

java.io.Serializable, Mappable<V>, Tensor<V>, Tensoric<V>

public class ImmutableTensor<V>
extends AbstractTensor<V>
implements Mappable<V>, java.io.Serializable

Default Implementation of Tensor.

By constraint of creation it holds a map of Position of certain type to values of type T, such that ALL Positions contains the same number and type of coordinates. Number and type of coordinates can be accessed and explored via Shape.

There is a special type of Tensor that has ZERO dimensiality. Can be obtained via factory method.

ImmutableTensor is immutable.

The toString() method does not print all the tensor entries.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ImmutableTensor.Builder<V> A builder for an immutable tensor.

Method Summary

Modifier and Type	Method and Description
java.util.Map<Position,V>	asMap() By implementing this method, a tensor can provide an efficient way to convert the tensor to a map from position to values.
static <T> ImmutableTensor.Builder<T>	builder(java.lang.Class<?>... dimensions) Returns a builder for an ImmutableTensor.
static <T> ImmutableTensor.Builder<T>	builder(java.lang.Iterable<java.lang.Class<?>> dimensions) Returns a builder for an ImmutableTensor.
static <T> ImmutableTensor.Builder<T>	builderFrom(Tensor<T> tensor) Returns a builder for an ImmutableTensor which is initiliased with the given ImmutableTensor.
boolean	contains(Position position) Returns true if the tensoric object contains the given position, false otherwise.
Position	context() Retrieves the context of the tensor, which is nothing else than a position.
static <T> Tensor<T>	copyOf(Tensor<T> tensor) Creates an immutable copy of the given tensor.
static <T> Tensor<T>	fromMap(java.lang.Iterable<java.lang.Class<?>> dimensions, java.util.Map<Position,T> map) Creates a tensor from the given map, where the map has to contain the positions as keys and the values as values.
V	get(Position position)
Shape	shape() Retrieves the shape of the tensor.
java.lang.String	toString() When printing the tensor content output is automatically not larger then N ant the beginning and N at the end of the Tensor entries.

Methods inherited from class org.tensorics.core.tensor.AbstractTensor

equals, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.tensorics.core.tensor.Tensoric

contains, get

Method Detail

builder

public static final <T> ImmutableTensor.Builder<T> builder(java.lang.Iterable<java.lang.Class<?>> dimensions)

Returns a builder for an ImmutableTensor. As argument it takes set of class of coordinates which represent the dimensions of the tensor.

Type Parameters:

T - type of values in Tensor.

Parameters:

dimensions - a set of classes that can later be used as coordinates for the tensor entries.

Returns:

a builder for ImmutableTensor

builder

public static final <T> ImmutableTensor.Builder<T> builder(java.lang.Class<?>... dimensions)

Returns a builder for an ImmutableTensor. The dimensions (classes of coordinates) of the future tensor have to be given as arguments here.

Type Parameters:

T - the type of values of the tensor

Parameters:

dimensions - the dimensions of the tensor to create

Returns:

a builder for an immutable tensor

fromMap

public static final <T> Tensor<T> fromMap(java.lang.Iterable<java.lang.Class<?>> dimensions,
                                          java.util.Map<Position,T> map)

Creates a tensor from the given map, where the map has to contain the positions as keys and the values as values.

Parameters:

dimensions - the desired dimensions of the tensor. This has to be consistent with the position - keys in the map.

map - the map from which to construct a tensor

Returns:

a new immutable tensor

copyOf

public static final <T> Tensor<T> copyOf(Tensor<T> tensor)

Creates an immutable copy of the given tensor.

Parameters:

tensor - the tensor whose element to copy

Returns:

new immutable Tensor

builderFrom

public static <T> ImmutableTensor.Builder<T> builderFrom(Tensor<T> tensor)

Returns a builder for an ImmutableTensor which is initiliased with the given ImmutableTensor.

Type Parameters:

T - type of values in Tensor.

Parameters:

tensor - a Tensor with which the ImmutableTensor.Builder is initialized

Returns:

a ImmutableTensor.Builder for an ImmutableTensor

get

public V get(Position position)

Specified by:

get in interface Tensoric<V>

Parameters:

position - the position in the N-dimensional space where to find the value.

Returns:

the value at the given position

context

public Position context()

Description copied from interface: Tensor

Retrieves the context of the tensor, which is nothing else than a position. As context of the tensor we understand coordinates within a higher dimensional space than than the tensor has itself. This coordinates can e.g. transport information when e.g. a higher-dimensional tensor is split into smaller ones, so that it can potentially be reconstructed afterwards.

Implementations have to guarantee that the returned value here is never null.

Specified by:

context in interface Tensor<V>

Returns:

the context of the tensor.

asMap

public java.util.Map<Position,V> asMap()

Description copied from interface: Mappable

By implementing this method, a tensor can provide an efficient way to convert the tensor to a map from position to values. Implementing instances must follow the following contract:

• this method must not return null
• It is recommended to return either a copy or an immutable map. Despite clients are not supposed to manipulate the returned maps, it cannot be guaranteed and this could lead to unexpected results.

Usually, clients will not use this method directly, but should use TensorInternals.mapFrom(Tensor) (internal clients) or Tensorics.mapFrom(Tensor) (external clients)

Specified by:

asMap in interface Mappable<V>

Returns:

a (preferrably immutable) map representing the content of the tensor

See Also:

TensorInternals.mapFrom(Tensor), Tensorics.mapFrom(Tensor)

shape

public Shape shape()

Description copied from interface: Tensor

Retrieves the shape of the tensor. As shape we understand simply the structure of a tensor: Its dimensions and the available positions.

Implementations have to take care that the returned value here is never null.

Specified by:

shape in interface Tensor<V>

Returns:

the shape of the tensor.

toString

public java.lang.String toString()

When printing the tensor content output is automatically not larger then N ant the beginning and N at the end of the Tensor entries.

Overrides:

toString in class java.lang.Object

contains

public boolean contains(Position position)

Description copied from interface: Tensoric

Returns true if the tensoric object contains the given position, false otherwise.

Specified by:

contains in interface Tensoric<V>

Parameters:

position - the position to be checked

Returns:

true if the position is contained in the tensoric object, false otherwise.