# fitted(to:validateOn:eventHandler:) Fits a time series classifier model to a sequence of examples. ``` func fitted(to input: some Sequence, Label>>, validateOn validation: some Sequence, Label>>, eventHandler: EventHandler? = nil) async throws -> TimeSeriesClassifier.Model ``` ## Parameters `input` A sequence of annotated features for training. Each feature’s shape should be `[sequenceLength, featureSize]`. `validation` A sequence of annotated features for validating. Each feature’s shape should be `[sequenceLength, featureSize]`. `eventHandler` An event handler. ## Return Value The fitted time series classifier model. ## Discussion The training process partitions the input into random batches according to the batch size configuration parameter. Training stops when the validation loss stops improving or when the maximum number of iterations is reached. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)