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Date: Thu, 22 Oct 2009 19:41:07 +0200
From: Ettos &lt;matmailRIMUOVIQUESTO@europe.com&gt;
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Hi all,
I'm new to matlab FFT algorithm, I'm doing some tests with a simple sine 
function. I've got two questions: one about amplitude and the other 
about phase.
The code is this:

wave = sin(linspace(0,2*pi,100));
fs = 10000; % Sampling frequency
n = length(wave);
Y = fft(wave);
A = 2*abs(Y)/n; % Amplitude spectrum
phase = angle(Y)*180/pi;

1) Why am I getting amplitude A(2) = 1 only if I multiply abs(Y) by 2?

2) Why am I getting phase(2) = -90 and not zero?

Thank you very much!
Matteo.
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