Storing the peak values of a fft

I have produced a code that will analyse vibration data. What I want to do is record the peak values of the FFT and store them so I can produce a graph showing the peak values of various runs of vibration data.

[Adam]

What is your problem in doing this? Isn't it just

max( abs( y ) )

where y is your fft result for a given input?

Answer 1

[Matt]

Hi Gavin

You can find local maxima by using the "findpeaks" function in MATLAB. Below is an example:

x = linspace(0,8*pi);
y = sin(x)./x;
[m,idx] = findpeaks(y);

plot(x,y)
hold on
plot(x(idx),y(idx),'ro')
hold off

You could apply this function to your fft output to find peaks.

Matt

[Gavin Lewis]

Thanks for the reply i keep getting this error = parse_inputs(isInMATLAB,Yin,varargin{:});