Re: Re: low-pass filter

From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>
Date: Wed, 20 Sep 2006 09:11:36 -0600 (MDT)

>actually,i don't understand the meaning of the
>function filwgts_lancos's options and the relationship
>among these options.the options are set wrong if i want
>a filter that "removes fluctuations with periods less
>than 10 years(11-point smooth)". cuold you give me any advice?
>thank you ! thank Adam !
>yours sherry

Your question is not clear.

You want a low pass filter: set fca appropriately
                            fcb is not used
                            opt=0 is good enough

If you have daily or monthly data I doubt there is any
way an 11- point filter can be designed that will
"remove fluctuations with periods less
than 10 years(11-point smooth)"

The reference for the Lancos filtering is:

Reference: C. Duchon
J. Applied Meteorology; August,1979;
pp 1016-1022
Lancos Filtering in One and Two Dimensions

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