Hi,
FFT for any signal has real and imaginary party, if input signal is even then fft is real and for odd signal fft is imaginary, so for composite signals fft has both real and imaginary signals
To observe real part of fft, use
>>Y=real(fft(w));
To observe imaginary part of fft, use
>>Y=imag(fft(w));
To observe both use abs to fft
>>Y=abs(fft(w));
To change the sampling frequency in the code change ta
ta=1/6000
Use the following to plot fft
t1 = linspace(-pi,pi,length(s)); % frequency spectrum is either -pi to pi or 0 to 2*pi
Y=real(fft(w));
