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Predictive and Specialized Modeling > Time Series Analysis > Statistical Details for the Time Series Platform > Statistical Details for Spectral Density
Publication date: 09/28/2021

Statistical Details for Spectral Density

The least squares estimates of the coefficients of the Fourier series are computed as follows:

Equation shown here

Equation shown here

Then the fi = i/N are combined to form the periodogram I(fi) = (N/2)(ai2 + bi2), which represents the intensity at frequency fi.

The periodogram is then smoothed and scaled by 1/(4π) to form the spectral density.

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