I have generated data in a FFT spectrum with this code. I want to filter out the fundamental frequency (set it to near 0) to then display the current oscillation without the fundamental oscillation.
The problem is that after reducing the values to 1e-15 (to be able to neglect them) I get complex values in the back transformation. Decreasing or increasing the range of values gives the same result.
Now the question would be whether it is at all possible to implement my project, or what must be done so that it works.
T = 250000;
f = 1/T
L = length(FILE00000132.MessNameSprung2);
VoltageL1 = FILE00000132.MessNameSprung2; %Current
YFFT = fft(CurrentL1);
P2 = abs(YFFT/L);
P1 = P2(1:L/2+1);
P1(2:length(P1)-1) = 2*P1(2:length(P1)-1);
f = T * (0:(L/2))/L;
plot(f,P1)
xlim([0 1000])
loglog(f,P1)
%YIFFT1 = ifft(YFFT)
YFFT(2:100) = 1e-15;
YFFT(356866:356966) =1e-15 %Set the values to 1e-15 to be able to neglect them
P2 = abs(YFFT/L);
P1 = P2(1:L/2+1);
P1(2:length(P1)-1) = 2*P1(2:length(P1)-1);
plot(f , P1 )
xlim([0 500])
loglog(f,P1)
YIFFT = ifft(Y); %Resulting in complex numbers
plot(f,YIFFT)
I have already read similar contributions to the FFT, but have not yet found what I was looking for with my problem.
