| If you search on “frequency response” in the ferret e-mail archives (http://ferret.pmel.noaa.gov/static/Ferret_search/ferret_mail_archives.html), you’ll find a contribution from me (http://www.pmel.noaa.gov/maillists/tmap/ferret_users/fu_2015/msg00055.html) on 17 Feb 2015 about a ferret script that gives an example of the frequency response of the LSL_Lowpass filter. As Billy Kessler pointed out, you will always lose some points off both ends of the filtered data. If the filter is symmetric and 2N+1 points wide, then the filtered data will have missing values at the first and last N points. I attach a slightly clearer version of that LSL Lowpass frequency response script here: |
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freq_response_function_lsl_lowpass.jnl
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------------------------------------------------------------------------------------------ Edward D. (Ned) Cokelet, Ph.D. Oceanographer NOAA/PMEL off: (206) 526-6820 7600 Sand Point Way NE fax: (206) 526-6485 Seattle, WA 98115-6349 Edward.D.Cokelet@xxxxxxxx The contents of this message are mine personally and do not necessarily reflect any position of the Government or the National Oceanic and Atmospheric Administration. |
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