- iOS 4.0+
- macOS 10.7+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
The number of complex elements to be transformed. This length must be one of:
f * 2n, where f is 3, 5, or 15 and n is at least 3.
The desired direction of the transform:
DSP _DFT _FORWARD
DSP _DFT _INVERSE
v object, or
NULL if the function fails, either from lack of memory or because
Length does not satisfy the requirement given above.
This function is designed to share memory between data structures where possible. If you have an existing setup object, you should pass that object as
Previous. By doing so, the returned setup object can share underlying data storage with that object. Note that this function may allocate memory; any allocated memory can ultimately be freed by