Re: [ferret_users] digital filtering using FFT

[Ryo Furue <furue@xxxxxxxxxx>]

Hi Yogesh,

Is there any utility in ferret which can do digital filtering of time series using FFT

I'm no expert in filtering, but I think there are FFT routines in Ferret.  You Fourier-transform your timeseries, mask out (or weaken) some Fourier components, and inverse-transform it.  You'll find documentations on Ferret's FFT routines on the website.

Having said that, you can often filter timeseries without going to the Fourier space.  Typical high-, low-, and band-pass filters are available in the forms of transformations or can be constructed from transformations.  For these, see the manual for the "@" transformations.

Ryo