# init(concatenating:alongAxis:) Concatenates `tensors` along the `axis` dimension. ``` init(concatenating tensors: some Collection, alongAxis axis: Int = 0) ``` ## Parameters `tensors` The tensors to concatenate. All tensors must have the same rank and all dimensions except `axis` must be equal. `axis` The axis along which to concatenate. Negative values wrap around but must be in the range `[-rank, rank)`, where `rank` is the rank of the provided tensors. ## Discussion For example: ```swift // t1 is [[1, 2, 3], [4, 5, 6]] // t2 is [[7, 8, 9], [10, 11, 12]] MLTensor(concatenating: [t1, t2]) // is [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10, 11, 12]] MLTensor(concatenating: [t1, t2], alongAxis: 1) // is [[1, 2, 3, 7, 8, 9], [4, 5, 6, 10, 11, 12]] // t3 has shape [2, 3] // t4 has shape [2, 3] MLTensor(concatenating: [t3, t4]) // has shape [4, 3] MLTensor(concatenating: [t3, t4], alongAxis: 1) // has shape [2, 6] ``` > Note: If you are concatenating along a new axis consider using > `MLTensor(stacking:alongAxis:)`. --- 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)