MajorityClass

class capymoa.classifier.MajorityClass

Bases: MOAClassifier

Majority class classifier.

Always predicts the class that has been observed most frequently the in the training data.

Example usages:

>>> from capymoa.datasets import ElectricityTiny
>>> from capymoa.classifier import MajorityClass
>>> from capymoa.evaluation import prequential_evaluation
>>> stream = ElectricityTiny()
>>> schema = stream.get_schema()
>>> learner = MajorityClass(schema)
>>> results = prequential_evaluation(stream, learner, max_instances=1000)
>>> results["cumulative"].accuracy()
50.2

__init__(schema: Schema | None = None)

Majority class classifier.

Parameters:

schema – The schema of the stream.

CLI_help()

predict(instance)

Predict the label of an instance.

The base implementation calls predict_proba() and returns the label with the highest probability.

Parameters:

instance – The instance to predict the label for.

Returns:

The predicted label or None if the classifier is unable to make a prediction.

predict_proba(instance)

Return probability estimates for each label.

Parameters:

instance – The instance to estimate the probabilities for.

Returns:

An array of probabilities for each label or None if the classifier is unable to make a prediction.

train(instance)

Train the classifier with a labeled instance.

Parameters:

instance – The labeled instance to train the classifier with.

random_seed: int

The random seed for reproducibility.

When implementing a classifier ensure random number generators are seeded.

schema: Schema

The schema representing the instances.