Re: How to change the phase "in degree" to the phase "in the time unit" when using specxy_anal?

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>Date: Sun, 4 Mar 2007 00:10:44 +0800

>I want to know how to change the phase " in the degree"( which is a attribute
>of return value when using specxy_anal)
>to the phase "in the time unit". For example, when I calculate the cross
>spectrum for 2 time series in a resolution of annual,
>I want to get their phase in the unit of year.

I am not quite sure but I'll take a shot.
[ncl-talk people: Please correct me.]

[1] In cross spectral analysis, the focus should be on
    frequencies where the *coherence* is significant.
    
[2] Let's just say that you have 100 years
    of annual values from two series and that
    the coherences are significant at frequencies
    corresponding to periods of 10-12.5 years.
    
[3] the phases corresponding to frequencies where coherences
    are significant are:

    (a) 0 : then x and y are 'in-phase' ... ie zero lag
    (b) 180 : then x leads y by 10-12.5 years
    (c) -180 : y x
    (d) 90 : x y 5-6.25
    (e) -90 : y x take a guess :-)
    
Good luck

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Received on Mon Mar 05 2007 - 16:55:59 MST