Function

vDSP_fft_zrop(_:_:_:_:_:_:_:)

Computes an out-of-place single-precision real discrete Fourier transform, either from the time domain to the frequency domain (forward) or from the frequency domain to the time domain (inverse).

Declaration

func vDSP_fft_zrop(_ __Setup: FFTSetup, _ __A: UnsafePointer<DSPSplitComplex>, _ __IA: vDSP_Stride, _ __C: UnsafePointer<DSPSplitComplex>, _ __IC: vDSP_Stride, _ __Log2N: vDSP_Length, _ __Direction: FFTDirection)

Parameters

__Setup

Points to a structure initialized by a prior call to the FFT setup data function, vDSP_create_fftsetup. The value supplied as parameter Log2n of the setup function must equal or exceed the value supplied as parameter Log2N of this transform function.

__A

Complex input vector.

__IA

Stride between elements in A. The value of IA should be 1 for best performance.

__C

Complex output vector.

__IC

Stride between elements in C. The value of IC should be 1 for best performance.

__Log2N

The base 2 exponent of the number of elements to process. For example, to process 1024 elements, specify 10 for parameter Log2N.

__Direction

A forward/inverse directional flag, which must specify kFFTDirection_Forward (+1) or kFFTDirection_Inverse (-1).

Discussion

This performs the following operation:

mathematical formula

where F is Direction, C is A, and N is two raised to the power of Log2N.

Forward transforms read real input and write packed complex output (see vDSP Programming Guide in vDSP Programming Guide for details on the packing format). Inverse transforms read packed complex input and write real output. As a result of packing the frequency-domain data, time-domain data and its equivalent frequency-domain data have the same storage requirements.

See also functions vDSP_create_fftsetup and vDSP_destroy_fftsetup.

See Also

1D Fast Fourier Transforms (Out-of-Place Real)

func vDSP_fft_zropD(FFTSetupD, UnsafePointer<DSPDoubleSplitComplex>, vDSP_Stride, UnsafePointer<DSPDoubleSplitComplex>, vDSP_Stride, vDSP_Length, FFTDirection)

Computes an out-of-place double-precision real discrete Fourier transform, either from the time domain to the frequency domain (forward) or from the frequency domain to the time domain (inverse).

func vDSP_fft_zropt(FFTSetup, UnsafePointer<DSPSplitComplex>, vDSP_Stride, UnsafePointer<DSPSplitComplex>, vDSP_Stride, UnsafePointer<DSPSplitComplex>, vDSP_Length, FFTDirection)

Computes an out-of-place single-precision real discrete Fourier transform, either from the time domain to the frequency domain (forward) or from the frequency domain to the time domain (inverse).

func vDSP_fft_zroptD(FFTSetupD, UnsafePointer<DSPDoubleSplitComplex>, vDSP_Stride, UnsafePointer<DSPDoubleSplitComplex>, vDSP_Stride, UnsafePointer<DSPDoubleSplitComplex>, vDSP_Length, FFTDirection)

Computes an out-of-place double-precision real discrete Fourier transform, either from the time domain to the frequency domain (forward) or from the frequency domain to the time domain (inverse).

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