From: Edward M. Reingold Date: Thu, 21 Sep 1995 02:46:47 +0000 (+0000) Subject: Added code to support Chinese calendar. X-Git-Tag: emacs-19.34~2816 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=8a45b040852b7982ed0c205553219efba66092a0;p=emacs.git Added code to support Chinese calendar. --- diff --git a/lisp/calendar/lunar.el b/lisp/calendar/lunar.el index 3167135d445..ab2cd6e4bc4 100644 --- a/lisp/calendar/lunar.el +++ b/lisp/calendar/lunar.el @@ -1,6 +1,6 @@ ;;; lunar.el --- calendar functions for phases of the moon. -;; Copyright (C) 1992, 1993 Free Software Foundation, Inc. +;; Copyright (C) 1992, 1993, 1995 Free Software Foundation, Inc. ;; Author: Edward M. Reingold ;; Keywords: calendar @@ -28,7 +28,8 @@ ;; diary.el. ;; Based on ``Astronomical Formulae for Calculators,'' 3rd ed., by Jean Meeus, -;; Willmann-Bell, Inc., 1985. +;; Willmann-Bell, Inc., 1985 and ``Astronomical Algorithms'' by Jean Meeus, +;; Willmann-Bell, Inc., 1991. ;; ;; WARNING: The calculations will be accurate only to within a few minutes. @@ -167,7 +168,7 @@ remainder mod 4 gives the phase: 0 new moon, 1 first quarter, 2 full moon, 60.0 24.0))) (time (* 24 (- date (truncate date)))) (date (calendar-gregorian-from-absolute (truncate date))) - (adj (solar-adj-time-for-dst date time))) + (adj (dst-adjust-time date time))) (list (car adj) (apply 'solar-time-string (cdr adj)) phase))) (defun lunar-phase-name (phase) @@ -247,6 +248,143 @@ This function is suitable for execution in a .emacs file." (concat (lunar-phase-name (car (cdr (cdr phase)))) " " (car (cdr phase)))))) + +;; For the Chinese calendar the calculations for the new moon need to be more +;; accurate than those above, so we use more terms in the approximation. + +(defun lunar-new-moon-time (k) + "Astronomical (Julian) day number of K th new moon." + (let* ((T (/ k 1236.85)) + (T2 (* T T)) + (T3 (* T T T)) + (T4 (* T2 T2)) + (JDE (+ 2451550.09765 + (* 29.530588853 k) + (* 0.0001337 T2) + (* -0.000000150 T3) + (* 0.00000000073 T4))) + (E (- 1 (* 0.002516 T) (* 0.0000074 T2))) + (sun-anomaly (+ 2.5534 + (* 29.10535669 k) + (* -0.0000218 T2) + (* -0.00000011 T3))) + (moon-anomaly (+ 201.5643 + (* 385.81693528 k) + (* 0.0107438 T2) + (* 0.00001239 T3) + (* -0.000000058 T4))) + (moon-argument (+ 160.7108 + (* 390.67050274 k) + (* -0.0016341 T2) + (* -0.00000227 T3) + (* 0.000000011 T4))) + (omega (+ 124.7746 + (* -1.56375580 k) + (* 0.0020691 T2) + (* 0.00000215 T3))) + (A1 (+ 299.77 (* 0.107408 k) (* -0.009173 T2))) + (A2 (+ 251.88 (* 0.016321 k))) + (A3 (+ 251.83 (* 26.641886 k))) + (A4 (+ 349.42 (* 36.412478 k))) + (A5 (+ 84.66 (* 18.206239 k))) + (A6 (+ 141.74 (* 53.303771 k))) + (A7 (+ 207.14 (* 2.453732 k))) + (A8 (+ 154.84 (* 7.306860 k))) + (A9 (+ 34.52 (* 27.261239 k))) + (A10 (+ 207.19 (* 0.121824 k))) + (A11 (+ 291.34 (* 1.844379 k))) + (A12 (+ 161.72 (* 24.198154 k))) + (A13 (+ 239.56 (* 25.513099 k))) + (A14 (+ 331.55 (* 3.592518 k))) + (correction + (+ (* -0.40720 (solar-sin-degrees moon-anomaly)) + (* 0.17241 E (solar-sin-degrees sun-anomaly)) + (* 0.01608 (solar-sin-degrees (* 2 moon-anomaly))) + (* 0.01039 (solar-sin-degrees (* 2 moon-argument))) + (* 0.00739 E (solar-sin-degrees (- moon-anomaly sun-anomaly))) + (* -0.00514 E (solar-sin-degrees (+ moon-anomaly sun-anomaly))) + (* 0.00208 E E (solar-sin-degrees (* 2 sun-anomaly))) + (* -0.00111 (solar-sin-degrees + (- moon-anomaly (* 2 moon-argument)))) + (* -0.00057 (solar-sin-degrees + (+ moon-anomaly (* 2 moon-argument)))) + (* 0.00056 E (solar-sin-degrees + (+ (* 2 moon-anomaly) sun-anomaly))) + (* -0.00042 (solar-sin-degrees (* 3 moon-anomaly))) + (* 0.00042 E (solar-sin-degrees + (+ sun-anomaly (* 2 moon-argument)))) + (* 0.00038 E (solar-sin-degrees + (- sun-anomaly (* 2 moon-argument)))) + (* -0.00024 E (solar-sin-degrees + (- (* 2 moon-anomaly) sun-anomaly))) + (* -0.00017 (solar-sin-degrees omega)) + (* -0.00007 (solar-sin-degrees + (+ moon-anomaly (* 2 sun-anomaly)))) + (* 0.00004 (solar-sin-degrees + (- (* 2 moon-anomaly) (* 2 moon-argument)))) + (* 0.00004 (solar-sin-degrees (* 3 sun-anomaly))) + (* 0.00003 (solar-sin-degrees (+ moon-anomaly sun-anomaly + (* -2 moon-argument)))) + (* 0.00003 (solar-sin-degrees + (+ (* 2 moon-anomaly) (* 2 moon-argument)))) + (* -0.00003 (solar-sin-degrees (+ moon-anomaly sun-anomaly + (* 2 moon-argument)))) + (* 0.00003 (solar-sin-degrees (- moon-anomaly sun-anomaly + (* -2 moon-argument)))) + (* -0.00002 (solar-sin-degrees (- moon-anomaly sun-anomaly + (* 2 moon-argument)))) + (* -0.00002 (solar-sin-degrees + (+ (* 3 moon-anomaly) sun-anomaly))) + (* 0.00002 (solar-sin-degrees (* 4 moon-anomaly))))) + (additional + (+ (* 0.000325 (solar-sin-degrees A1)) + (* 0.000165 (solar-sin-degrees A2)) + (* 0.000164 (solar-sin-degrees A3)) + (* 0.000126 (solar-sin-degrees A4)) + (* 0.000110 (solar-sin-degrees A5)) + (* 0.000062 (solar-sin-degrees A6)) + (* 0.000060 (solar-sin-degrees A7)) + (* 0.000056 (solar-sin-degrees A8)) + (* 0.000047 (solar-sin-degrees A9)) + (* 0.000042 (solar-sin-degrees A10)) + (* 0.000040 (solar-sin-degrees A11)) + (* 0.000037 (solar-sin-degrees A12)) + (* 0.000035 (solar-sin-degrees A13)) + (* 0.000023 (solar-sin-degrees A14)))) + (newJDE (+ JDE correction additional))) + (+ newJDE + (- (solar-ephemeris-correction + (extract-calendar-year + (calendar-gregorian-from-absolute + (floor (calendar-absolute-from-astro newJDE)))))) + (/ calendar-time-zone 60.0 24.0)))) + +(defun lunar-new-moon-on-or-after (d) + "Astronomical (Julian) day number of first new moon on or after astronomical +(Julian) day number d. The fractional part is the time of day. + +The date and time are local time, including any daylight savings rules, +as governed by the values of calendar-daylight-savings-starts, +calendar-daylight-savings-starts-time, calendar-daylight-savings-ends, +calendar-daylight-savings-ends-time, calendar-daylight-time-offset, and +calendar-time-zone." + (let* ((date (calendar-gregorian-from-absolute + (floor (calendar-absolute-from-astro d)))) + (year (+ (extract-calendar-year date) + (/ (calendar-day-number date) 365.25))) + (k (floor (* (- year 2000.0) 12.3685))) + (date (lunar-new-moon-time k))) + (while (< date d) + (setq k (1+ k)) + (setq date (lunar-new-moon-time k))) + (let* ((a-date (calendar-absolute-from-astro date)) + (time (* 24 (- a-date (truncate a-date)))) + (date (calendar-gregorian-from-absolute (truncate a-date))) + (adj (dst-adjust-time date time))) + (calendar-astro-from-absolute + (+ (calendar-absolute-from-gregorian (car adj)) + (/ (car (cdr adj)) 24.0)))))) + (provide 'lunar) ;;; lunar.el ends here