Package com.yahoo.tensor

Class MappedTensor

java.lang.Object

com.yahoo.tensor.MappedTensor

All Implemented Interfaces:

Tensor

public class MappedTensor
extends Object
implements Tensor

A sparse implementation of a tensor backed by a Map of cells to values.

Author:

bratseth

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MappedTensor.Builder

Nested classes/interfaces inherited from interface com.yahoo.tensor.Tensor

Tensor.Cell

Field Summary

Fields inherited from interface com.yahoo.tensor.Tensor

invalidIndex

Method Summary

Modifier and Type	Method	Description
Iterator<Tensor.Cell>	cellIterator()	Returns the cell of this in some undefined order.
Map<TensorAddress,Double>	cells()	Returns an immutable map of the cells of this in no particular order.
boolean	equals(Object other)	Returns whether this tensor and the given tensor is mathematically equal: That they have the same dimension *names* and the same content.
double	get(TensorAddress address)	Returns the value of a cell, or 0.0 if this cell does not exist
Double	getAsDouble(TensorAddress address)	Returns the value at this address, or null of it does not exist.
boolean	has(TensorAddress address)	Returns true if this cell exists
int	hashCode()	Returns a hash computed deterministically from the content of this tensor
Tensor	remove(Set<TensorAddress> addresses)	Returns a new tensor where existing cells in this tensor have been removed according to the given set of addresses.
long	size()	Returns the number of cells in this, allowing for very large tensors.
int	sizeAsInt()	Once we can store more cells than an int we should drop this.
String	toAbbreviatedString(boolean withType, boolean shortForms)	Returns an abbreviated string representation of this tensor suitable for human-readable messages
String	toString()	Returns this tensor on the tensor literal form with type included.
String	toString(boolean withType, boolean shortForms)	Returns this tensor on the tensor literal form.
TensorType	type()
Iterator<Double>	valueIterator()	Returns the values of this in some undefined order
Tensor	withType(TensorType other)	Returns this tensor with the given type if types are compatible

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.yahoo.tensor.Tensor

add, approxEqual, argmax, argmin, asDouble, atan2, avg, avg, avg, bit, cellCast, concat, concat, count, count, count, divide, equal, expand, fmod, hamming, isEmpty, join, l1Normalize, l2Normalize, larger, largerOrEqual, largest, ldexp, map, matmul, max, max, max, max, median, median, median, merge, min, min, min, min, modify, multiply, notEqual, pow, prod, prod, prod, reduce, reduce, rename, rename, smaller, smallerOrEqual, smallest, softmax, subtract, sum, sum, sum, toAbbreviatedString, xwPlusB

Method Details

type

public TensorType type()

Specified by:

type in interface Tensor

size

public long size()

Description copied from interface: Tensor

Returns the number of cells in this, allowing for very large tensors. Prefer sizeAsInt in implementations that cannot handle sizes outside the int range.

Specified by:

size in interface Tensor

sizeAsInt

public int sizeAsInt()

Once we can store more cells than an int we should drop this.

Specified by:

sizeAsInt in interface Tensor

get

public double get(TensorAddress address)

Description copied from interface: Tensor

Returns the value of a cell, or 0.0 if this cell does not exist

Specified by:

get in interface Tensor

has

public boolean has(TensorAddress address)

Description copied from interface: Tensor

Returns true if this cell exists

Specified by:

has in interface Tensor

getAsDouble

public Double getAsDouble(TensorAddress address)

Description copied from interface: Tensor

Returns the value at this address, or null of it does not exist.

Specified by:

getAsDouble in interface Tensor

cellIterator

public Iterator<Tensor.Cell> cellIterator()

Description copied from interface: Tensor

Returns the cell of this in some undefined order. A cell instance is only valid until next() is called. Call detach() on the cell to obtain a long-lived instance.

Specified by:

cellIterator in interface Tensor

valueIterator

public Iterator<Double> valueIterator()

Description copied from interface: Tensor

Returns the values of this in some undefined order

Specified by:

valueIterator in interface Tensor

cells

public Map<TensorAddress,Double> cells()

Description copied from interface: Tensor

Returns an immutable map of the cells of this in no particular order. This may be expensive for some implementations - avoid when possible

Specified by:

cells in interface Tensor

withType

public Tensor withType(TensorType other)

Description copied from interface: Tensor

Returns this tensor with the given type if types are compatible

Specified by:

withType in interface Tensor

remove

public Tensor remove(Set<TensorAddress> addresses)

Description copied from interface: Tensor

Returns a new tensor where existing cells in this tensor have been removed according to the given set of addresses. Only valid for mapped or mixed tensors. For mixed tensors, addresses are assumed to only contain the mapped dimensions, as the entire indexed subspace is removed.

Specified by:

remove in interface Tensor

Parameters:

addresses - list of addresses to remove

Returns:

a new tensor where cells have been removed

hashCode

public int hashCode()

Description copied from interface: Tensor

Returns a hash computed deterministically from the content of this tensor

Specified by:

hashCode in interface Tensor

Overrides:

hashCode in class Object

toString

public String toString()

Description copied from interface: Tensor

Returns this tensor on the tensor literal form with type included.

Specified by:

toString in interface Tensor

Overrides:

toString in class Object

toString

public String toString(boolean withType,
 boolean shortForms)

Description copied from interface: Tensor

Returns this tensor on the tensor literal form.

Specified by:

toString in interface Tensor

Parameters:

withType - whether to prefix the value by the type of this

shortForms - whether to use short forms where applicable, or always using the verbose form

toAbbreviatedString

public String toAbbreviatedString(boolean withType,
 boolean shortForms)

Description copied from interface: Tensor

Returns an abbreviated string representation of this tensor suitable for human-readable messages

Specified by:

toAbbreviatedString in interface Tensor

Parameters:

withType - whether to prefix the value by the type of this

shortForms - whether to use short forms where applicable, or always using the verbose form

equals

public boolean equals(Object other)

Description copied from interface: Tensor

Returns whether this tensor and the given tensor is mathematically equal: That they have the same dimension *names* and the same content.

Specified by:

equals in interface Tensor

Overrides:

equals in class Object