how to make fourier power spectrum of the time series??

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Ali Nouri 2020-2-14

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回答： Raunak Gupta 2020-2-19

I have a vector, which include different amplitude for whole a year, now I want to analyze these amplitudes with fourier analysis.

Anybody knows how to do it ??

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Jakob B. Nielsen 2020-2-14

Check out the fft function.

Ali Nouri 2020-2-18

But how can I define sampling frequency and the other parameter??

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Answer 1

Raunak Gupta 2020-2-19

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Hi,

Since you want to use Fourier analysis for the vector mentioned in the question, it suggests that the data have some periodicity and you may want to know the period of the signal. I suggest using fft for getting the frequency component of the signal.

To mention the sampling frequency, you may follow the Nyquist criteria for sampling which state that the sampling frequency must be greater than or equal to twice the highest frequency in the signal. So, you may mention a high frequency value based on knowledge of the signal.

For getting started you may follow this example.