[R-sig-finance] more fCalendar

[Spencer Graves]

	  If you have not received a reply to this and your other similar post, 
I suggest you send a private email to the Maintainer:    Diethelm Wuertz 
<wuertz at itp.phys.ethz.ch>.

	  I would think he would appreciate your contribution.

	  Good Luck,
	  spencer graves

Parlamis Franklin wrote:

> It's me again, with Japanese calendar minutiae I'm sure you've all  
> been dying to brush up on.
> 
> the fCalendar functions don't include the Japanese Vernal Equinox  
> holiday.  this is perhaps because there is no easy way to calculate  
> it.  at any rate, here's a function i wrote to fill the gap.
> 
> =====
> 
> JPVernalEquinox <- function(year) {
> 
>      ##  Origin and End Date data from http://aa.usno.navy.mil/data/ 
> docs/EarthSeasons.html
>      ##  The function Vernal.Equinox delivers correct values at the  
> endpoints of the above data.
>      ##  There may be minor variances (+/- a few minutes) in the  
> intermediate values,
>      ##  because the function linearly approximates a phenomenon that  
> is apparently
>      ##  nonlinear in recorded time.
> 
>      Equinox.Origin <- timeCalendar(1992, 3, 20, 8, 48, 0,  
> FinCenter="GMT")
>      Data.EndDate <- timeCalendar(2020,3,20,3,49,0,FinCenter="GMT")
>      Total.Seconds <- as.numeric(Data.EndDate-Equinox.Origin)*24*60*60
>      Mean.Annual.Seconds <- Total.Seconds/(atoms(Data.EndDate)$Y-atoms 
> (Equinox.Origin)$Y)
>      Vernal.Equinox <- function(year) Equinox.Origin+unclass((year- 
> atoms(Equinox.Origin)$Y)*Mean.Annual.Seconds)
>      JPVernal.Equinox <- function(year) timeDate(as.character 
> (Vernal.Equinox(year)), FinCenter="Tokyo")
> 
>      ## Nota bene:  JP Vernal Equinox is celebrated when the equinox  
> occurs in the Japanese time zone
>      ## (see, e.g., 2006, where GMT Vernal Equinox is on 20 March,  
> but Japanese Equinox holiday is 21 March)
> 
>      as.Date(as.character(JPVernal.Equinox(year)))}
> 
> =====
> 
> in contrast to the other holiday functions in fCalendar, the above  
> function returns an object of class "Date" rather than "sdate"  
> because use of sdates appears to be deprecated following the  
> introduction of the Date class, and also because the sdate function  
> appears to have a bug.
> 	[[alternative HTML version deleted]]
> 
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-- 
Spencer Graves, PhD
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