# init(concatenating:alongAxis:) Merges a sequence of shaped arrays into one shaped array along an axis. ``` init(concatenating shapedArrays: S, alongAxis: Int) where Scalar == S.Element.Scalar, S : Sequence, S.Element : MLShapedArrayProtocol ``` ## Parameters `shapedArrays` A sequence of shaped arrays. `alongAxis` A zero-based axis number the shaped arrays in `multiArray` merge along. > Tip: > Select the shaped array’s highest dimension by passing a negative axis number. For example, an axis value of `-1` or `-2` selects the last or second-to-last dimension, respectively. ## Discussion All shaped arrays in the sequence must have the following: - The same underlying data type - The same number of dimensions - The same size for each corresponding dimension, except for the concatenation axis For example, this code concatenates two shaped arrays along their second dimension: ```swift // A 2x3 shaped array. // 0 1 2 // 5 6 7 let shapedArray1 = MLShapedArray(scalars: [0, 1, 2, 5, 6, 7], shape: [2, 3]) // A 2x2 shaped array. // 3 4 // 8 9 let shapedArray2 = MLShapedArray(scalars: [3, 4, 8, 9], shape: [2, 2]) // A 2x5 shaped array. // 0 1 2 3 4 // 5 6 7 8 9 let shapedArray3 = MLShapedArray(concatenating: [shapedArray1,shapedArray2], alongAxis: 1) ``` --- 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)