amplitude of non-periodic signal

Dear All; if I have a non periodic signal/wave , how can i calculate the amplitude and wavelength ?

Answer 1

[Star Strider]

Another possibility is in the code I used in this Answer. The peak times (the periods are the differences between them) will be in t(zx_idx) and the amplitudes will be in C(zx_idx) in that code.

[mustafa alnasser]

Thank you but where is the code ?

[Star Strider]

It is in my Answer. I am reposting it here:

t = linspace(0, 10, 1000);                      % Time
C = 2 + sin(2*pi*t + cos(5*pi+t)*pi);           % Signal

dC = diff([0, C])/(t(2)-t(1));                  % Approximate Derivative
dCzx = dC .* circshift(dC, [0 -1]);             % Negative Values => Zero Crossings (Mostly)
zx_idx = find(dCzx <= 0);                       % Derivative Zeros Are Maxima, Minima Of ‘C’

figure(1)
plot(t, C)
hold on
plot(t(zx_idx), C(zx_idx), 'or')
hold off
grid
axis([xlim    0  5])

Answer 2

[Image Analyst]

As you know, any arbitrary signal can be considered as a weighted sum of a bunch of sine waves - that's the whole concept of Fourier analysis. I suggestion you look at the fft() function or the pwelch() function.

[mustafa alnasser]

Thank you but where is the code ?

[mustafa alnasser]

sorry for the second answer.

For your answer i have already did that but i could not figure out how use FFT to do that