# TimeSeriesForecasterBatches A sequence of forecaster batches on a time series shaped array. ``` struct TimeSeriesForecasterBatches where Scalar : MLShapedArrayScalar ``` ## Overview A time-series forecaster takes a series of samples and produces a prediction of the next samples. For example the sequence `[1, 2, 3, 4]` could predict `[5, 6]`. To train a forecaster, each training batch contains the input samples along with the annotations (ground truth predictions). For example a batch could have this: ``` features = [ [1, 2, 3, 4], [2, 3, 4, 5], [3, 4, 5, 6], ] annotations = [ [5, 6], [6, 7], [7, 8], ] ``` The shape of the features in the sequence is `[batchSize, inputWindowSize, featureSize]` and the shape of the annotations is `[batchSize, forecastWindowSize, annotationSize]`. The batch sequence will return as many feature-annotation examples as fit in the input. For example, an input sequence size of 10 with an input sample count of 4 and a prediction sample count of 2 will produce 5 examples: ``` features: [1, 2, 3, 4], annotations: [5, 6] features: [2, 3, 4, 5], annotations: [6, 7] features: [3, 4, 5, 6], annotations: [7, 8] features: [4, 5, 6, 7], annotations: [8, 9] features: [5, 6, 7, 8], annotations: [9, 10] ``` Note that 9 and 10 are never used as features because there would be no annotations for those examples. ## Topics ### Creating a time series forecaster batch [`init(features: MLShapedArray, annotations: MLShapedArray, batchSize: Int, inputWindowSize: Int, forecastWindowSize: Int, shufflesBatches: Bool) throws`](/documentation/CreateMLComponents/TimeSeriesForecasterBatches/init(features:annotations:batchSize:inputWindowSize:forecastWindowSize:shufflesBatches:)) Creates a batch sequence. ### Inspecting a time series forecaster batch [`let annotations: MLShapedArray`](/documentation/CreateMLComponents/TimeSeriesForecasterBatches/annotations) The original annotations. [`let batchSize: Int`](/documentation/CreateMLComponents/TimeSeriesForecasterBatches/batchSize) The batch size. [`let features: MLShapedArray`](/documentation/CreateMLComponents/TimeSeriesForecasterBatches/features) The original features. [`let forecastWindowSize: Int`](/documentation/CreateMLComponents/TimeSeriesForecasterBatches/forecastWindowSize) The prediction sample count. [`let inputWindowSize: Int`](/documentation/CreateMLComponents/TimeSeriesForecasterBatches/inputWindowSize) The input sample count. [`var shufflesBatches: Bool`](/documentation/CreateMLComponents/TimeSeriesForecasterBatches/shufflesBatches) A Boolean value indicating whether to shuffle the batches. ### Default Implementations [Sequence Implementations](/documentation/CreateMLComponents/TimeSeriesForecasterBatches/Sequence-Implementations) ## Relationships ### Conforms To [`Sequence`](/documentation/Swift/Sequence) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Sendable`](/documentation/Swift/Sendable) --- 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)