org.tribuo.impl

Class ArrayExample<T extends Output<T>>

java.lang.Object

org.tribuo.Example<T>

org.tribuo.impl.ArrayExample<T>

All Implemented Interfaces:

Serializable, Iterable<Feature>

Direct Known Subclasses:

IndexedArrayExample

public class ArrayExample<T extends Output<T>>
extends Example<T>

An Example backed by two arrays, one of String and one of double.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_SIZE
protected String[]	featureNames
protected double[]	featureValues
protected int	size

Fields inherited from class org.tribuo.Example

DEFAULT_METADATA_SIZE, DEFAULT_WEIGHT, metadata, NAME, output, weight

Constructor Summary

Constructors

Constructor and Description
ArrayExample(Example<T> other) Copy constructor.
ArrayExample(T output) Constructs an example from an output.
ArrayExample(T output, Example<U> other, float weight) Clones an example's features, but uses the supplied output and weight.
ArrayExample(T output, float weight) Constructs an example from an output and a weight.
ArrayExample(T output, float weight, int initialSize) Constructs an example from an output and a weight, with an initial size for the feature arrays.
ArrayExample(T output, float weight, Map<String,Object> metadata) Constructs an example from an output, a weight and the metadata.
ArrayExample(T output, List<? extends Feature> features) Constructs an example from an output and a list of features.
ArrayExample(T output, Map<String,Object> metadata) Constructs an example from an output and the metadata.
ArrayExample(T output, String[] names, double[] values) Constructs an example from an output, an array of names and an array of values.

Method Summary

Modifier and Type	Method and Description
void	add(Feature feature) Adds a feature.
void	add(String name, double value) Adds a single feature.
void	addAll(Collection<? extends Feature> features) Adds a collection of features.
void	canonicalize(FeatureMap featureMap) Reassigns feature name Strings in the Example to point to those in the FeatureMap.
ArrayExample<T>	copy() Returns a deep copy of this Example.
double[]	copyValues(int newSize) Returns a copy of the feature values array at the specific size.
void	densify(List<String> featureList) Converts all implicit zeros into explicit zeros based on the supplied feature names.
boolean	equals(Object o)
protected void	growArray() Grows the backing arrays by size+1.
protected void	growArray(int minCapacity) Grows the backing arrays storing the names and values.
int	hashCode()
boolean	isDense(FeatureMap fMap) Is this example dense wrt the supplied feature map.
Iterator<Feature>	iterator()
Feature	lookup(String i) Returns the Feature in this Example which has the supplied name, if it's present.
protected int	newCapacity(int minCapacity) Returns a capacity at least as large as the given minimum capacity.
void	reduceByName(Merger merger) Merges features with the same name using the supplied Merger.
void	removeFeatures(List<Feature> featureList) Removes all features in this list from the Example.
void	set(Feature feature) Overwrites the feature with the matching name.
int	size() Return how many features are in this example.
protected void	sort() Sorts the feature list to maintain the lexicographic order invariant.
String	toString()
void	transform(TransformerMap transformerMap) Transforms this example by applying the transformations from the supplied TransformerMap.
boolean	validateExample() Checks the example to see if all the feature names are unique, the feature values are not NaN, and there is at least one feature.

Methods inherited from class org.tribuo.Example

containsMetadata, densify, getMetadata, getMetadataValue, getOutput, getWeight, setMetadataValue, setWeight

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

DEFAULT_SIZE

public static final int DEFAULT_SIZE

See Also:

Constant Field Values

featureNames

protected String[] featureNames

featureValues

protected double[] featureValues

size

protected int size

Constructor Detail

ArrayExample

public ArrayExample(T output,
                    float weight,
                    int initialSize)

Constructs an example from an output and a weight, with an initial size for the feature arrays.

Parameters:

output - The output.

weight - The weight.

initialSize - The initial size of the feature arrays.

ArrayExample

public ArrayExample(T output,
                    float weight,
                    Map<String,Object> metadata)

Constructs an example from an output, a weight and the metadata.

Parameters:

output - The output.

weight - The weight.

metadata - The metadata.

ArrayExample

public ArrayExample(T output,
                    float weight)

Constructs an example from an output and a weight.

Parameters:

output - The output.

weight - The example weight.

ArrayExample

public ArrayExample(T output,
                    Map<String,Object> metadata)

Constructs an example from an output and the metadata.

Parameters:

output - The output.

metadata - The metadata.

ArrayExample

public ArrayExample(T output)

Constructs an example from an output.

Parameters:

output - The output.

ArrayExample

public ArrayExample(T output,
                    String[] names,
                    double[] values)

Constructs an example from an output, an array of names and an array of values. This is currently the most efficient constructor.

Parameters:

output - The output.

names - The feature names.

values - The feature values.

ArrayExample

public ArrayExample(T output,
                    List<? extends Feature> features)

Constructs an example from an output and a list of features.

Parameters:

output - The output.

features - The list of features.

ArrayExample

public ArrayExample(Example<T> other)

Copy constructor.

Parameters:

other - The example to copy.

ArrayExample

public ArrayExample(T output,
                    Example<U> other,
                    float weight)

Clones an example's features, but uses the supplied output and weight.

Type Parameters:

U - The output type of the other example.

Parameters:

output - The output to use.

other - The features to use.

weight - The weight to use.

Method Detail

add

public void add(String name,
                double value)

Adds a single feature.

Parameters:

name - The name of the feature.

value - The value of the feature.

add

public void add(Feature feature)

Description copied from class: Example

Adds a feature. This maintains the sorted invariant and has a lg(example.size()) cost per insertion.

Specified by:

add in class Example<T extends Output<T>>

Parameters:

feature - The feature to add.

addAll

public void addAll(Collection<? extends Feature> features)

Description copied from class: Example

Adds a collection of features. This maintains the sorted invariant but is more efficient than adding one at a time due to allocation.

Specified by:

addAll in class Example<T extends Output<T>>

Parameters:

features - The features to add.

growArray

protected void growArray(int minCapacity)

Grows the backing arrays storing the names and values.

Parameters:

minCapacity - The new minimum capacity required.

growArray

protected void growArray()

Grows the backing arrays by size+1.

newCapacity

protected int newCapacity(int minCapacity)

Returns a capacity at least as large as the given minimum capacity. Returns the current capacity increased by 50% if that suffices. Will not return a capacity greater than MAX_ARRAY_SIZE unless the given minimum capacity is greater than MAX_ARRAY_SIZE.

Parameters:

minCapacity - the desired minimum capacity

Returns:

The new capacity.

Throws:

OutOfMemoryError - if minCapacity is less than zero

sort

protected void sort()

Sorts the feature list to maintain the lexicographic order invariant.

Specified by:

sort in class Example<T extends Output<T>>

copyValues

public double[] copyValues(int newSize)

Returns a copy of the feature values array at the specific size.

Parameters:

newSize - The new size.

Returns:

A copy of the feature values.

size

public int size()

Description copied from class: Example

Return how many features are in this example.

Specified by:

size in class Example<T extends Output<T>>

Returns:

The number of features.

removeFeatures

public void removeFeatures(List<Feature> featureList)

Description copied from class: Example

Removes all features in this list from the Example.

Specified by:

removeFeatures in class Example<T extends Output<T>>

Parameters:

featureList - Features to remove from this Example.

reduceByName

public void reduceByName(Merger merger)

Description copied from class: Example

Merges features with the same name using the supplied Merger.

Specified by:

reduceByName in class Example<T extends Output<T>>

Parameters:

merger - A function to merge two doubles.

validateExample

public boolean validateExample()

Description copied from class: Example

Checks the example to see if all the feature names are unique, the feature values are not NaN, and there is at least one feature.

Specified by:

validateExample in class Example<T extends Output<T>>

Returns:

true if the example is valid.

copy

public ArrayExample<T> copy()

Description copied from class: Example

Returns a deep copy of this Example.

Specified by:

copy in class Example<T extends Output<T>>

Returns:

A deep copy of this example.

lookup

public Feature lookup(String i)

Description copied from class: Example

Returns the Feature in this Example which has the supplied name, if it's present.

Overrides:

lookup in class Example<T extends Output<T>>

Parameters:

i - The feature name to lookup.

Returns:

The feature object.

set

public void set(Feature feature)

Description copied from class: Example

Overwrites the feature with the matching name.

Throws IllegalArgumentException if there isn't a feature with that name in this example.

Specified by:

set in class Example<T extends Output<T>>

Parameters:

feature - The new feature value.

transform

public void transform(TransformerMap transformerMap)

Description copied from class: Example

Transforms this example by applying the transformations from the supplied TransformerMap.

Can be overridden for performance reasons.

Overrides:

transform in class Example<T extends Output<T>>

Parameters:

transformerMap - The transformations to apply.

isDense

public boolean isDense(FeatureMap fMap)

Description copied from class: Example

Is this example dense wrt the supplied feature map.

An example is "dense" if it contains all the features in the map, and only those features.

Specified by:

isDense in class Example<T extends Output<T>>

Parameters:

fMap - The feature map to check against.

Returns:

True if this example contains only the features in the map, and all the features in the map.

densify

public void densify(List<String> featureList)

Description copied from class: Example

Converts all implicit zeros into explicit zeros based on the supplied feature names.

Specified by:

densify in class Example<T extends Output<T>>

Parameters:

featureList - A *sorted* list of feature names.

iterator

public Iterator<Feature> iterator()

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

canonicalize

public void canonicalize(FeatureMap featureMap)

Description copied from class: Example

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

Specified by:

canonicalize in class Example<T extends Output<T>>

Parameters:

featureMap - The feature map containing canonical feature names.