radix 2 disspation in frequency

for K=0:7
    for N=0:3
        if mod(K,2)==0
            v(N+1)=(x(N+1)+x(N+5))*exp(-1i*N*K*pi/2);
        elseif  mod(K,2)==1
             v(N+1)=((x(N+1)-x(N+5))*exp(-1i*N*pi/4))*exp(-1i*N*K*pi/2);
       end

      end
  Y(K+1)=sum(v);
  end

i assume that is radix 2 disspation in frequency what's wron in it

[Walter Roberson]

Are you seeing an error message? If not then what difference do you see between what you are getting and what you expected?

[ayman osama]

no i didn'y got an error msg i should have fft of x what i see that the first term in fft is right and other terms are wrong i was using dissipation in frequency teq.

Answer 1

[Azzi Abdelmalek]

x=rand(1,8);    % Example
xo=x(2:2:end);  % odd part
xe=x(1:2:end);  % even part
for N=0:3
  for k=0:3
     Xo(k+1)=xo(k+1)*exp(-j*2*k*N*pi/4)
     Xe(k+1)=xe(k+1)*exp(-j*2*k*N*pi/4)
  end
  Yo(N+1)=sum(Xo)
  Ye(N+1)=sum(Xe)
  Y(N+1)=Ye(N+1)+exp(-j*2*N*pi/n)*Yo(N+1)
  Y(N+5)=Ye(N+1)-exp(-j*2*N*pi/n)*Yo(N+1)
end