**Name**

**fft1d** Compute the Fast Fourier Transform of a complex signal

**Command Synopsis**

**fft1d** [-i] [-I *Xi*] [-A *Yr*] [-B *Yi*] *Xr*

-i : Compute the Inverse Transform

-IXi: Input signal (imaginary part)

-AYr: Output signal (real part)

-BYi: Output signal (imaginary part)

Xr: Input signal (real part)

**Function Summary**

void fft1d (Xr , Xi , Yr , Yi , inverse )

Fsignal Xr , Xi , Yr , Yi ;

char *inverse ;

**Description**

This module computes the Discrete Fourier Transform of a complex signal using the fast algorithm based on the one given in [PFTV88]. It can also compute the Inverse Discrete Fourier Transform, by selecting the appropriate switch. Notice that, in this module, complex signals are represented by two fsignals: the first one contains the real part of the signal and the second one contains its imaginary part.

**See Also**

`fct1d`, `fft2d`, `fftrot`, `stkwave1`.

**Version 1.2**

Last Modification date : Tue Apr 8 04:40:31 2003

**Author**

Chiaa Babya, Jacques Froment, Lionel Moisan