# TimeSeriesForecasterAnnotatedWindows A sequence of forecasting windows on a time series shaped array. ``` struct TimeSeriesForecasterAnnotatedWindows 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]`. The shape of each feature in the sequence is `[inputWindowSize, featureSize]` and the shape of each annotation is `[forecastWindowSize, annotationSize]`. The sequence will return as many feature-annotation examples as fit in the input. For example an input sequence of size of 10 with an input sample count of 4, a prediction sample count of 2, and a stride of 1 will produce 5 annotated windows: ``` feature: [1, 2, 3, 4], annotation: [5, 6] feature: [2, 3, 4, 5], annotation: [6, 7] feature: [3, 4, 5, 6], annotation: [7, 8] feature: [4, 5, 6, 7], annotation: [8, 9] feature: [5, 6, 7, 8], annotation: [9, 10] ``` Note that 9 and 10 are never used as features because there would be no annotations for those samples. ## Topics ### Creating a time series forecaster annotated window [`init(features: MLShapedArray, annotations: MLShapedArray, inputWindowSize: Int, forecastWindowSize: Int, stride: Int, shufflesElements: Bool) throws`](/documentation/CreateMLComponents/TimeSeriesForecasterAnnotatedWindows/init(features:annotations:inputWindowSize:forecastWindowSize:stride:shufflesElements:)) Creates a batch sequence. ### Inspecting a time series forecaster annotated window [`let annotations: MLShapedArray`](/documentation/CreateMLComponents/TimeSeriesForecasterAnnotatedWindows/annotations) The original annotations. [`let features: MLShapedArray`](/documentation/CreateMLComponents/TimeSeriesForecasterAnnotatedWindows/features) The original features. [`let forecastWindowSize: Int`](/documentation/CreateMLComponents/TimeSeriesForecasterAnnotatedWindows/forecastWindowSize) The prediction sample count. [`let inputWindowSize: Int`](/documentation/CreateMLComponents/TimeSeriesForecasterAnnotatedWindows/inputWindowSize) The input sample count. [`var shufflesElements: Bool`](/documentation/CreateMLComponents/TimeSeriesForecasterAnnotatedWindows/shufflesElements) A Boolean value indicating whether to shuffle the elements. [`var stride: Int`](/documentation/CreateMLComponents/TimeSeriesForecasterAnnotatedWindows/stride) The number of samples between windows. ### Default Implementations [Sequence Implementations](/documentation/CreateMLComponents/TimeSeriesForecasterAnnotatedWindows/Sequence-Implementations) ## Relationships ### Conforms To [`Sequence`](/documentation/Swift/Sequence) [`Sendable`](/documentation/Swift/Sendable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) --- 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)