# vvcos(_:_:_:) Calculates the cosine of each element in an array of double-precision values. ``` func vvcos(_: UnsafeMutablePointer, _: UnsafePointer, _: UnsafePointer) ``` ## Discussion ### Parameters: - parameter 1: The output array, *y*. - parameter 2: The input array, *x*. - parameter 3: The number of elements in the arrays. If `x` is `+/-inf`, the result is `NaN`. The following code shows an example of using [`vvcos(_:_:_:)`](/documentation/Accelerate/vvcos(_:_:_:)). ```swift let pi = Double.pi var x: [Double] = [-pi, 0, pi] var y = [Double](repeating: 0, count: x.count) var n = Int32(x.count) vvcos(&y, &x, &n) print(y) // [-1.0, 0.0, 1.0] ``` --- 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)