The fft of 3 functions are compared with their analytic transforms. The method proposal produce results that are super imposable with the theoretical predictions.
Odd and even number of points are considered.
(The algorithm works correctly in both cases).

I get same results when using
X1=fftshift(fft(fftshift(x1)));
X2=fftshift(fft(fftshift(x2)));
X=X1+X2;
xo = ifftshift(ifft(ifftshift(X)))
OR
X1=(fft((x1)));
X2=(fft((x2)));
X=X1+X2;
xo = (ifft((X)))

My intervals are symmetric and power of 2.
Are these correct and is this normal in matlab 2013b?

its very good - explains finally why we need fftshift twice. However, it should be stressed that the method works only for data of even size. For odd size data, the amplitude is correct but spectral phase will be wrong.

Excellent description of the theory of the FFT.
But my code threw up errors...cannot define functions at this point?? Could not run it now. I will have to look into it a little.

05 Mar 2008

li taotao

Great,I like this file very much

18 Jun 2007

Fabrice Chane-Ming

21 Mar 2007

M. Ashrith Kumar

its very good !! but slightly need for improvement

27 Feb 2007

B. Roossien

It's a good start, but the script contains the "clear all" and "close all" commands, which is a very bad habit to do.

03 Jan 2007

Andrey Worobey

Thanks so much man!!!

I have been looking for the solution for a year!

30 Dec 2006

Vishnuvenkatesh Dhage

15 Dec 2006

Yani Jerome

I've found FourierTransform.m (ID 13327) very usefull too

24 Nov 2006

you you

30 Oct 2006

ilaria eos

21 Sep 2006

michel sebes

31 Oct 2005

ISABEL CRISTINA GOMEZ

Gracias

15 Oct 2005

Wynn Ko Ko

Need to be improved.

29 Sep 2005

Gunasekaran Shanmgam

Gives nice overview of all FFT's

06 Aug 2005

samudrala jagadeesh

this is a good file for the users also beginers for filter designers thanks for the support

21 Jun 2005

srinu jella

u guys r impoptant for students like us. because we are in the initial stage of learning.we can learn from u .