# vvcopysign(_:_:_:_:) Copies an array, setting the sign of each element based on a second array of double-precision values. ``` func vvcopysign(_: UnsafeMutablePointer, _: UnsafePointer, _: UnsafePointer, _: UnsafePointer) ``` ## Discussion ### Parameters: - parameter 1: The output array, *z*. - parameter 2: The magnitude input array, *y*. - parameter 3: The sign input array, *x*. - parameter 4: The number of elements in the arrays. The following code shows an example of using [`vvcopysign(_:_:_:_:)`](/documentation/Accelerate/vvcopysign(_:_:_:_:)). ```swift var x: [Double] = [-1, -1, 1, 1] var y: [Double] = [1.2, 5.5, -16, 26.0] var z = [Double](repeating: 0, count: x.count) var n = Int32(x.count) vvcopysign(&z, &y, &x, &n) print(z) // [-1.2, -5.5, 16.0, 26.0] ``` --- 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)