can someone explain to me what this code means??

Its actually a guitar tuner made by Ryann Kinnett. I tried to interact with him but unfortunately his e-mail is out. Anyway, I think I know what the program does at certain lines but mostly what I am struggling to figure out is the FFT section...

here is the links to the program http://www.mathworks.com/matlabcentral/fileexchange/26367-guitar-tuner/content/GuitarTuner.m

go to "download submisson" at the upper right if you want to run it on matlab

Cheers!!

[Jan]

What exactly is your question? I suggest to post the corresponding line, explain, what you have understood so far and ask a specific question.

[John Bitzios]

I dont get the fft section... to be specific i am referring to the following lines:

NFFT=2^nextpow2(L);

fftdata=abs(fft(data,NFFT)/L;

the default code matlab gives is

NFFT = 2^nextpow2(L);

Y = fft(y,NFFT)/L;

So, the only thing that changes is the absolute value...why would he do so??

Answer 1

[dpb]

2/L*abs(Y(1:NFFT/2+1)))

gives a one-sided (DC to Nyquist) amplitude spectrum. The above is the two-sided version from [-Nyquist:Nyquist] with DC in the middle.

Answer 2

[John Bitzios]

What about the while gcbo command???