Re: [ferret_users] Fourier harmonics

[William Kessler <william.s.kessler@xxxxxxxx>]

Here are two old scripts that find individual harmonics algebraically: 
 
Least -squares fit time series to C + Asin(wt) + Bcos(wt), where C is the mean, w is omega.
 
The first one (harm-6b.go) works for regular data with no blanks (then C is the simple time average).
The second (harm-blank.go) handles irregular time series with blanks and incomplete years (lots of ugly cross-terms, and the mean is part of the fit).
 
These do not plot anything, just set up variables. Output listing tells you how to use the defined variables.
 
Billy K
 
 
> On Apr 28, 2019, at 12:08 AM, Pratik Kad <pratikkad17@xxxxxxxxx> wrote:
> 
> Dear all
> 
> I am trying to extract the semiannual harmonics from time series. I did Fourier analysis by referring ef_fft_demo. Is there any possible way in ferret to get Fourier harmonics? 
> Please suggest. 
> 
> Regards,
> Pratik Kad

Attachment: harm-6b.go
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Attachment: harm-blank.go
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