# MATLAB Matlab-Plot Power Spectrum of time series

#### pigasos54

Hi all,

and thank you for reading/responding to my thread.I have a problem which involves time series and its power spectra.

Some background:
I have an 10.000xN matrix(called matr) whose columns are individual time series with real data values and I want to plot their power spectra against frequency.These time series where generated by an iterative map which involved a sin function with omega=0.1. Plotting freq versus power I might be able to see if any harmonics are present.

Below are the steps I take in Matlab:

y=fft(matr) % get the fourier transform of the matrix
y=(abs(y)).^2 %this is the power spectra

Is the above right?

Also I'm puzzled as to what frequency range I should use.
Does
freq=(0:10000-1)/10000
seems right?

Any suggestions?
Thank you all

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