On 11/15/2012 2:33 AM, oversky wrote: > The mathwork fft example in the following link, > http://bit.ly/SO9TuV > why do we double abs(Y(1:NFFT/2+1) when plotting the amplitude? > > plot(f,2*abs(Y(1:NFFT/2+1))) >

This was talked about before. can google it. Here is my take on it: