# vDSP_hamm_windowD Creates a double-precision Hamming window. ``` extern void vDSP_hamm_windowD(double *__C, vDSP_Length __N, int __Flag); ``` ## Parameters `__C` The output vector. `__N` The number of elements in the output vector. `__Flag` A value that specifies whether the function creates a half window or a full window. Pass the flag to create only the first `(N+1)/2` points; pass `0` to create a full-size window. ## Discussion The [`vDSP_hamm_window`](/documentation/Accelerate/vDSP_hamm_window) and [`vDSP_hamm_windowD`](/documentation/Accelerate/vDSP_hamm_windowD) functions create a Hamming window vector using the following operation: ```objc for (n=0; n < N; ++n) { C[n] = 0.54 - (0.46 * cos( 2 * pi * n / N ) ); } ``` The following code shows how to generate a Hamming window: ```swift let n = vDSP_Length(1024) var c = [Float](repeating: 0, count: Int(n)) vDSP_hamm_window(&c, n, 0) ``` The following illustrates the values of the output vector, `c`:  --- 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)