fft problem (conjugates)

[Sengupta Sourav]

Hi all,

Had a qn..when i perform an fft on say an 8 pt
sequence(radix 2) we get the results as say

X(0), X(1), X(2)...X(7)

now we expect X(1) and X(7) to be conjugates and..

X(3) and X(5) to also be conjugates, also

X(0) = sum of all the elements of the 8 pt input
sequence etc..

when i gave a real series as the input..this worked
fine,with the fft results satisfying the abovebut when
i gave a complex sequence as the i/p to the fft..this
is what i got 

  1 + 0i  2 + 0i  3 - 1i  0 + 0i  1 + 0i  2 + 1i  2 +
0i  0 - 1i

octave:15> k
k =

 Columns 1 through 3:

   11.00000 -  1.00000i   -1.00000 -  2.41421i  
-1.00000 -  3.00000i

 Columns 4 through 6:

    1.00000 +  2.41421i    3.00000 -  1.00000i  
-1.00000 +  0.41421i

 Columns 7 and 8:

   -5.00000 +  5.00000i    1.00000 -  0.41421i

where a is the input and k=fft(a)=fft(a,8), clearly
the conditions are not satisfied..if anyone knows the
problem plzz mail me.

Thanks in advance,

Sourav

=====
Sourav Sengupta

__________________________________________________
Do You Yahoo!?
Make international calls for as low as $.04/minute with Yahoo! Messenger
http://phonecard.yahoo.com/



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------