Subj : FFT  Fourier code
To   : comp.programming.threads
From : attackack
Date : Fri Jan 14 2005 02:50 am

Hallo

I'm trying to implemet the code about FFT or DFT but i can't
understand how is possible to calculate the real and the imaginary
parameter from a list of number that describe a waveform.
For example if i have a list of number like this and suppose a time
between data of one second:

0
10
20
30
20
10
0
-10
-20
....

now i need the real and the imaginary component from them to use FFT
of DFT function that is like this:

int DFT(int dir,int m,double *x1,double *y1)
{
....
}

where 
double *x1 = real component
double *y1 = imaginary component

I've tryed to calculate these components but i get erroneous results.

Exist a code or similar that do it?

If you haven't this code can you tell me if you know some place in the
web where is possible to find this kind of code?

At this moment i've found only complicated mathematical formulas. Not
for me.

Thanks

.