org.tribuo.sequence

Class SequenceExample<T extends Output<T>>

java.lang.Object

org.tribuo.sequence.SequenceExample<T>

All Implemented Interfaces:

Serializable, Iterable<Example<T>>

public class SequenceExample<T extends Output<T>>
extends Object
implements Iterable<Example<T>>, Serializable

A sequence of examples, used for sequence classification.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static float	DEFAULT_WEIGHT

Constructor Summary

Constructors

Constructor and Description
SequenceExample() Creates an empty sequence example.
SequenceExample(List<Example<T>> examples) Creates a sequence example from the list of examples.
SequenceExample(List<Example<T>> examples, float weight) Creates a sequence example from the list of examples, setting the weight.
SequenceExample(List<T> outputs, List<? extends List<? extends Feature>> features) Creates a sequence example from the supplied outputs and list of list of features.
SequenceExample(List<T> outputs, List<? extends List<? extends Feature>> features, boolean attemptBinaryFeatures)
SequenceExample(List<T> outputs, List<? extends List<? extends Feature>> features, float weight) Creates a sequence example from the supplied weight, outputs and list of list of features.
SequenceExample(List<T> outputs, List<? extends List<? extends Feature>> features, float weight, boolean attemptBinaryFeatures)
SequenceExample(SequenceExample<T> other) Creates a deep copy of the supplied sequence example.

Method Summary

Modifier and Type	Method and Description
void	addExample(Example<T> e) Adds an Example to this sequence.
void	canonicalise(FeatureMap featureMap) Reassigns feature name Strings in each Example inside this SequenceExample to point to those in the FeatureMap.
SequenceExample<T>	copy() Returns a deep copy of this SequenceExample.
static <T extends Output<T>> SequenceExample<T>	createWithEmptyOutputs(List<? extends List<? extends Feature>> features, OutputFactory<T> outputFactory) Creates a SequenceExample using OutputFactory.getUnknownOutput() as the output for each sequence element.
Iterator<Feature>	featureIterator() Creates an iterator over every feature in this sequence.
Example<T>	get(int i) Gets the example found at the specified index.
float	getWeight() Gets the weight of this sequence.
Iterator<Example<T>>	iterator()
void	reduceByName(Merger merger) Reduces the features in each example using the supplied Merger.
void	removeFeatures(List<Feature> features) Removes the features in the supplied list from each example contained in this sequence.
void	setWeight(float weight) Sets the weight of this sequence.
int	size() Return how many examples are in this sequence.
boolean	validateExample() Checks that each Example in this sequence is valid.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

DEFAULT_WEIGHT

public static final float DEFAULT_WEIGHT

See Also:

Constant Field Values

Constructor Detail

SequenceExample

public SequenceExample()

Creates an empty sequence example.

SequenceExample

public SequenceExample(List<Example<T>> examples)

Creates a sequence example from the list of examples.

The examples are not copied by this method.

Parameters:

examples - The examples to incorporate.

SequenceExample

public SequenceExample(List<Example<T>> examples,
                       float weight)

Creates a sequence example from the list of examples, setting the weight.

The examples are encapsulated by this constructor, not copied.

Parameters:

examples - The examples to incorporate.

weight - The weight of this sequence.

SequenceExample

public SequenceExample(List<T> outputs,
                       List<? extends List<? extends Feature>> features)

Creates a sequence example from the supplied outputs and list of list of features.

The features are copied out by this constructor. The outputs and features lists must be of the same length. Sets the weight to DEFAULT_WEIGHT.

Parameters:

outputs - The outputs for each sequence element.

features - The features for each sequence element.

SequenceExample

public SequenceExample(List<T> outputs,
                       List<? extends List<? extends Feature>> features,
                       float weight)

Creates a sequence example from the supplied weight, outputs and list of list of features.

The features are copied out by this constructor. The outputs and features lists must be of the same length.

Parameters:

outputs - The outputs for each sequence element.

features - The features for each sequence element.

weight - The weight for this sequence example.

SequenceExample

public SequenceExample(List<T> outputs,
                       List<? extends List<? extends Feature>> features,
                       boolean attemptBinaryFeatures)

SequenceExample

public SequenceExample(List<T> outputs,
                       List<? extends List<? extends Feature>> features,
                       float weight,
                       boolean attemptBinaryFeatures)

SequenceExample

public SequenceExample(SequenceExample<T> other)

Creates a deep copy of the supplied sequence example.

Parameters:

other - The sequence example to copy.

Method Detail

size

public int size()

Return how many examples are in this sequence.

Returns:

The number of examples.

removeFeatures

public void removeFeatures(List<Feature> features)

Removes the features in the supplied list from each example contained in this sequence.

Parameters:

features - The features to remove.

get

public Example<T> get(int i)

Gets the example found at the specified index.

Parameters:

i - The index to lookup.

Returns:

The Example for index i.

validateExample

public boolean validateExample()

Checks that each Example in this sequence is valid.

Returns:

True if each Example is valid, false otherwise.

reduceByName

public void reduceByName(Merger merger)

Reduces the features in each example using the supplied Merger.

Parameters:

merger - The merger to use in the reduction.

setWeight

public void setWeight(float weight)

Sets the weight of this sequence.

Parameters:

weight - The new weight.

getWeight

public float getWeight()

Gets the weight of this sequence.

Returns:

The weight of this sequence.

addExample

public void addExample(Example<T> e)

Adds an Example to this sequence.

Parameters:

e - The example to add.

copy

public SequenceExample<T> copy()

Returns a deep copy of this SequenceExample.

Returns:

A deep copy.

iterator

public Iterator<Example<T>> iterator()

Specified by:

iterator in interface Iterable<Example<T extends Output<T>>>

featureIterator

public Iterator<Feature> featureIterator()

Creates an iterator over every feature in this sequence.

Returns:

An iterator over features.

canonicalise

public void canonicalise(FeatureMap featureMap)

Reassigns feature name Strings in each Example inside this SequenceExample to point to those in the FeatureMap. This significantly reduces memory allocation. It is called when a SequenceExample is added to a MutableSequenceDataset, and should not be called outside of that context as it may interact unexpectedly with HashedFeatureMap.

Parameters:

featureMap - The feature map containing canonical feature names.

createWithEmptyOutputs

public static <T extends Output<T>> SequenceExample<T> createWithEmptyOutputs(List<? extends List<? extends Feature>> features,
                                                                              OutputFactory<T> outputFactory)

Creates a SequenceExample using OutputFactory.getUnknownOutput() as the output for each sequence element.

Note: this method is used to create SequenceExamples at prediction time where there is no ground truth Output.

Type Parameters:

T - The type of the Output.

Parameters:

features - The features for each sequence element.

outputFactory - The output factory to use.

Returns:

A new SequenceExample.