# vSndot(_:_:_:_:_:_:) Computes the dot products of n pairs of vectors, accumulating or storing the results in an array of `n` `float` values. ``` func vSndot(_ n: Int32, _ m: Int32, _ s: UnsafeMutablePointer, _ isw: Int32, _ x: UnsafePointer, _ y: UnsafePointer) ``` ## Parameters `n` Number of dot products to compute, and number of elements in vector `s` ; must be a multiple of 4. `m` Number of elements in the vectors whose dot products are computed; must be a multiple of 4. `s` Destination vector; the `n` dot products are accumulated or stored here. `isw` A key that selects one of the four variants of this function: see Discussion below. `x` A matrix whose rows are `n` floating-point vectors, each containing `m` values. `y` A second matrix whose rows are `n` floating-point vectors, each containing `m` values. ## Discussion For i = 0 to n-1, the dot product of vectors `x`[i] and `y`[i] is computed. The dot product is accumulated or stored in `s`[i], according to the value of `isw`: - if `isw` = 1, the dot product is stored in `s`[i]. - if `isw` = 2, the dot product is negated and then stored in `s`[i]. - if `isw` = 3, the dot product is added to the value in `s`[i]. - if `isw` = 4, the dot product is negated and then added to the value in `s`[i]. --- 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)