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

void vDSP_fft_zrop(FFTSetup __Setup, const DSPSplitComplex *__A, vDSP_Stride __IA, const DSPSplitComplex *__C, vDSP_Stride __IC, vDSP_Length __Log2N, FFTDirection __Direction);

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)

vDSP_fft_zropD

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).

vDSP_fft_zropt

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).

vDSP_fft_zroptD

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).

vDSP_fftm_zrop

Performs the same operation as vDSP_fft_zrop, but on multiple signals with a single call.

vDSP_fftm_zropD

Performs the same operation as VDSP_fft_zropD, but on multiple signals with a single call.

vDSP_fftm_zropt

Performs the same operation as VDSP_fft_zropt, but on multiple signals with a single call.

vDSP_fftm_zroptD

Performs the same operation as VDSP_fft_zroptD, but on multiple signals with a single call.