Package org.tribuo.classification.sequence.viterbi

Class ViterbiModel

java.lang.Object

org.tribuo.sequence.SequenceModel<Label>

org.tribuo.classification.sequence.viterbi.ViterbiModel

All Implemented Interfaces:

com.oracle.labs.mlrg.olcut.provenance.Provenancable<ModelProvenance>, Serializable, ProtoSerializable<org.tribuo.protos.core.SequenceModelProto>

public class ViterbiModel
extends SequenceModel<Label>

An implementation of a viterbi model.

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	ViterbiModel.ScoreAggregation	Types of label score aggregation.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	CURRENT_VERSION	Protobuf serialization version.

Fields inherited from class org.tribuo.sequence.SequenceModel

featureIDMap, name, outputIDMap, provenanceOutput

Fields inherited from interface org.tribuo.protos.ProtoSerializable

DESERIALIZATION_METHOD_NAME, PROVENANCE_SERIALIZER

Method Summary

Modifier and Type	Method	Description
static ViterbiModel	deserializeFromProto(int version, String className, com.google.protobuf.Any message)	Deserialization factory.
Model<Label>	getInnerModel()	Returns the inner model used for sequence element predictions.
ViterbiModel.ScoreAggregation	getScoreAggregation()	Gets the score aggregation function.
int	getStackSize()	Gets the stack size of this model.
Map<String,List<com.oracle.labs.mlrg.olcut.util.Pair<String,Double>>>	getTopFeatures(int n)	Gets the top n features associated with this model.
protected List<Label>	getTopLabels(Map<String,Label> distribution)	Gets the most likely labels.
protected static List<Label>	getTopLabels(Map<String,Label> distribution, int stackSize)	Gets the stackSize most likely labels.
List<List<Prediction<Label>>>	predict(SequenceDataset<Label> examples)	Uses the model to predict the labels for multiple examples contained in a data set.
List<Prediction<Label>>	predict(SequenceExample<Label> examples)	Uses the model to predict the output for a single example.
org.tribuo.protos.core.SequenceModelProto	serialize()	Serializes this object to a protobuf.

Methods inherited from class org.tribuo.sequence.SequenceModel

castModel, createDataCarrier, deserialize, deserializeFromFile, deserializeFromStream, getFeatureIDMap, getName, getOutputIDInfo, getProvenance, predict, serializeToFile, serializeToStream, setName, toMaxLabels, toString, validate

Methods inherited from class java.lang.Object

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

Field Details

CURRENT_VERSION

public static final int CURRENT_VERSION

Protobuf serialization version.

See Also:

• Constant Field Values

Method Details

deserializeFromProto

public static ViterbiModel deserializeFromProto(int version,
 String className,
 com.google.protobuf.Any message)
                                         throws com.google.protobuf.InvalidProtocolBufferException

Deserialization factory.

Parameters:

version - The serialized object version.

className - The class name.

message - The serialized data.

Returns:

The deserialized object.

Throws:

com.google.protobuf.InvalidProtocolBufferException - If the protobuf could not be parsed from the message.

predict

public List<List<Prediction<Label>>> predict(SequenceDataset<Label> examples)

Description copied from class: SequenceModel

Uses the model to predict the labels for multiple examples contained in a data set.

Overrides:

predict in class SequenceModel<Label>

Parameters:

examples - the data set containing the examples to predict.

Returns:

the results of the predictions, in the same order as the data set generates the example.

predict

public List<Prediction<Label>> predict(SequenceExample<Label> examples)

Description copied from class: SequenceModel

Uses the model to predict the output for a single example.

Specified by:

predict in class SequenceModel<Label>

Parameters:

examples - the example to predict.

Returns:

the result of the prediction.

getInnerModel

public Model<Label> getInnerModel()

Returns the inner model used for sequence element predictions.

Returns:

The inner model.

getTopLabels

protected List<Label> getTopLabels(Map<String,Label> distribution)

Gets the most likely labels.

Parameters:

distribution - The label distribution.

Returns:

The most likely labels in descending order.

getTopLabels

protected static List<Label> getTopLabels(Map<String,Label> distribution,
 int stackSize)

Gets the stackSize most likely labels.

Parameters:

distribution - The label distribution.

stackSize - The number of labels to pick.

Returns:

The most likely labels in descending order.

getStackSize

public int getStackSize()

Gets the stack size of this model.

Returns:

The stack size.

getScoreAggregation

public ViterbiModel.ScoreAggregation getScoreAggregation()

Gets the score aggregation function.

Returns:

The score aggregation function.

getTopFeatures

public Map<String,List<com.oracle.labs.mlrg.olcut.util.Pair<String,Double>>> getTopFeatures(int n)

Description copied from class: SequenceModel

Gets the top n features associated with this model.

If the model does not produce per output feature lists, it returns a map with a single element with key Model.ALL_OUTPUTS.

If the model cannot describe it's top features then it returns Collections.emptyMap().

Specified by:

getTopFeatures in class SequenceModel<Label>

Parameters:

n - the number of features to return. If this value is less than 0, all features should be returned for each class, unless the model cannot score its features.

Returns:

a map from string outputs to an ordered list of pairs of feature names and weights associated with that feature in the model

serialize

public org.tribuo.protos.core.SequenceModelProto serialize()

Description copied from interface: ProtoSerializable

Serializes this object to a protobuf.

Specified by:

serialize in interface ProtoSerializable<org.tribuo.protos.core.SequenceModelProto>

Overrides:

serialize in class SequenceModel<Label>

Returns:

The protobuf.