Class AdaBoostTrainer
java.lang.Object
org.tribuo.classification.ensemble.AdaBoostTrainer
- All Implemented Interfaces:
com.oracle.labs.mlrg.olcut.config.Configurable
,com.oracle.labs.mlrg.olcut.provenance.Provenancable<TrainerProvenance>
,Trainer<Label>
Implements Adaboost.SAMME one of the more popular algorithms for multiclass boosting.
Based on this paper.
If the trainer implements WeightedExamples
then it performs boosting by weighting,
otherwise it uses a weighted bootstrap sample.
See:
J. Zhu, S. Rosset, H. Zou, T. Hastie. "Multi-class Adaboost" 2006.
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected int
protected SplittableRandom
protected long
protected int
Fields inherited from interface org.tribuo.Trainer
DEFAULT_SEED
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Constructor Summary
ConstructorsConstructorDescriptionAdaBoostTrainer
(Trainer<Label> trainer, int numMembers) Constructs an adaboost trainer using the supplied weak learner trainer and the specified number of boosting rounds.AdaBoostTrainer
(Trainer<Label> trainer, int numMembers, long seed) Constructs an adaboost trainer using the supplied weak learner trainer, the specified number of boosting rounds and the supplied seed. -
Method Summary
Modifier and TypeMethodDescriptionint
The number of times this trainer instance has had it's train method invoked.void
toString()
train
(Dataset<Label> examples, Map<String, com.oracle.labs.mlrg.olcut.provenance.Provenance> runProvenance) If the trainer implementsWeightedExamples
then do boosting by weighting, otherwise do boosting by sampling.
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Field Details
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innerTrainer
@Config(mandatory=true, description="The trainer to use to build each weak learner.") protected Trainer<Label> innerTrainer -
numMembers
@Config(mandatory=true, description="The number of ensemble members to train.") protected int numMembers -
seed
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rng
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trainInvocationCounter
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Constructor Details
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AdaBoostTrainer
Constructs an adaboost trainer using the supplied weak learner trainer and the specified number of boosting rounds. Uses the default seed.- Parameters:
trainer
- The weak learner trainer.numMembers
- The maximum number of boosting rounds.
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AdaBoostTrainer
Constructs an adaboost trainer using the supplied weak learner trainer, the specified number of boosting rounds and the supplied seed.- Parameters:
trainer
- The weak learner trainer.numMembers
- The maximum number of boosting rounds.seed
- The RNG seed.
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Method Details
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postConfig
- Specified by:
postConfig
in interfacecom.oracle.labs.mlrg.olcut.config.Configurable
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toString
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train
public Model<Label> train(Dataset<Label> examples, Map<String, com.oracle.labs.mlrg.olcut.provenance.Provenance> runProvenance) If the trainer implementsWeightedExamples
then do boosting by weighting, otherwise do boosting by sampling.- Specified by:
train
in interfaceTrainer<Label>
- Parameters:
examples
- the data set containing the examples.runProvenance
- Training run specific provenance (e.g., fold number).- Returns:
- A
WeightedEnsembleModel
.
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getInvocationCount
Description copied from interface:Trainer
The number of times this trainer instance has had it's train method invoked.This is used to determine how many times the trainer's RNG has been accessed to ensure replicability in the random number stream.
- Specified by:
getInvocationCount
in interfaceTrainer<Label>
- Returns:
- The number of train invocations.
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getProvenance
- Specified by:
getProvenance
in interfacecom.oracle.labs.mlrg.olcut.provenance.Provenancable<TrainerProvenance>
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