;;; Commentary:
-;; This collection of functions implements lunar phases for calendar.el and
-;; diary.el.
+;; See calendar.el.
;; Based on ``Astronomical Formulae for Calculators,'' 3rd ed., by Jean Meeus,
;; Willmann-Bell, Inc., 1985 and ``Astronomical Algorithms'' by Jean Meeus,
;; The author would be delighted to have an astronomically more sophisticated
;; person rewrite the code for the lunar calculations in this file!
-;; Technical details of all the calendrical calculations can be found in
-;; ``Calendrical Calculations: The Millennium Edition'' by Edward M. Reingold
-;; and Nachum Dershowitz, Cambridge University Press (2001).
-
;;; Code:
-(defvar date)
-(defvar displayed-month)
-(defvar displayed-year)
-
-(if (fboundp 'atan)
- (require 'lisp-float-type)
- (error "Lunar calculations impossible since floating point is unavailable"))
-
+(require 'calendar)
(require 'solar)
-
-(defun lunar-phase-list (month year)
- "List of lunar phases for three months starting with Gregorian MONTH, YEAR."
- (let ((end-month month)
- (end-year year)
- (start-month month)
- (start-year year))
- (increment-calendar-month end-month end-year 3)
- (increment-calendar-month start-month start-year -1)
- (let* ((end-date (list (list end-month 1 end-year)))
- (start-date (list (list start-month
- (calendar-last-day-of-month
- start-month start-year)
- start-year)))
- (index (* 4
- (truncate
- (* 12.3685
- (+ year
- ( / (calendar-day-number (list month 1 year))
- 366.0)
- -1900)))))
- (new-moon (lunar-phase index))
- (list))
- (while (calendar-date-compare new-moon end-date)
- (if (calendar-date-compare start-date new-moon)
- (setq list (append list (list new-moon))))
- (setq index (1+ index))
- (setq new-moon (lunar-phase index)))
- list)))
+(require 'cal-dst)
+;; calendar-astro-to-absolute and v versa are cal-autoloads.
+;;;(require 'cal-julian)
(defun lunar-phase (index)
"Local date and time of lunar phase INDEX.
(* 0.0004 (solar-sin-degrees
(- sun-anomaly (* 2 moon-anomaly))))
(* -0.0003 (solar-sin-degrees
- (+ (* 2 sun-anomaly) moon-anomaly))))))
+ (+ (* 2 sun-anomaly) moon-anomaly))))))
(adj (+ 0.0028
(* -0.0004 (solar-cosine-degrees
sun-anomaly))
((= phase 2) (- adjustment adj))
(t adjustment)))
(date (+ date adjustment))
- (date (+ date (/ (- calendar-time-zone
- (solar-ephemeris-correction
+ (date (+ date (/ (- calendar-time-zone
+ (solar-ephemeris-correction
(extract-calendar-year
(calendar-gregorian-from-absolute
(truncate date)))))
- 60.0 24.0)))
+ 60.0 24.0)))
(time (* 24 (- date (truncate date))))
- (date (calendar-gregorian-from-absolute (truncate date)))
+ (date (calendar-gregorian-from-absolute (truncate date)))
(adj (dst-adjust-time date time)))
(list (car adj) (apply 'solar-time-string (cdr adj)) phase)))
+(defun lunar-phase-list (month year)
+ "List of lunar phases for three months starting with Gregorian MONTH, YEAR."
+ (let* ((end-month month)
+ (end-year year)
+ (start-month month)
+ (start-year year)
+ (end-date (progn
+ (increment-calendar-month end-month end-year 3)
+ (list (list end-month 1 end-year))))
+ (start-date (progn
+ (increment-calendar-month start-month start-year -1)
+ (list (list start-month
+ (calendar-last-day-of-month
+ start-month start-year)
+ start-year))))
+ (index (* 4 (truncate
+ (* 12.3685
+ (+ year
+ ( / (calendar-day-number (list month 1 year))
+ 366.0)
+ -1900)))))
+ (new-moon (lunar-phase index))
+ list)
+ (while (calendar-date-compare new-moon end-date)
+ (if (calendar-date-compare start-date new-moon)
+ (setq list (append list (list new-moon))))
+ (setq index (1+ index)
+ new-moon (lunar-phase index)))
+ list))
+
(defun lunar-phase-name (phase)
"Name of lunar PHASE.
0 = new moon, 1 = first quarter, 2 = full moon, 3 = last quarter."
((= 2 phase) "Full Moon")
((= 3 phase) "Last Quarter Moon")))
+(defvar displayed-month) ; from generate-calendar
+(defvar displayed-year)
+
+;;;###cal-autoload
(defun calendar-phases-of-moon ()
"Create a buffer with the lunar phases for the current calendar window."
(interactive)
(y2 displayed-year))
(increment-calendar-month m1 y1 -1)
(increment-calendar-month m2 y2 1)
- (set-buffer (get-buffer-create lunar-phases-buffer))
- (setq buffer-read-only nil)
- (calendar-set-mode-line
- (if (= y1 y2)
- (format "Phases of the Moon from %s to %s, %d%%-"
- (calendar-month-name m1) (calendar-month-name m2) y2)
- (format "Phases of the Moon from %s, %d to %s, %d%%-"
- (calendar-month-name m1) y1 (calendar-month-name m2) y2)))
- (erase-buffer)
- (insert
- (mapconcat
- (lambda (x)
- (let ((date (car x))
- (time (car (cdr x)))
- (phase (car (cdr (cdr x)))))
- (concat (calendar-date-string date)
- ": "
- (lunar-phase-name phase)
- " "
- time)))
- (lunar-phase-list m1 y1) "\n"))
- (goto-char (point-min))
- (set-buffer-modified-p nil)
- (setq buffer-read-only t)
- (display-buffer lunar-phases-buffer)
+ (calendar-in-read-only-buffer lunar-phases-buffer
+ (calendar-set-mode-line
+ (if (= y1 y2)
+ (format "Phases of the Moon from %s to %s, %d%%-"
+ (calendar-month-name m1) (calendar-month-name m2) y2)
+ (format "Phases of the Moon from %s, %d to %s, %d%%-"
+ (calendar-month-name m1) y1 (calendar-month-name m2) y2)))
+ (insert
+ (mapconcat
+ (lambda (x)
+ (let ((date (car x))
+ (time (cadr x))
+ (phase (nth 2 x)))
+ (concat (calendar-date-string date)
+ ": "
+ (lunar-phase-name phase)
+ " "
+ time)))
+ (lunar-phase-list m1 y1) "\n")))
(message "Computing phases of the moon...done")))
;;;###autoload
This function is suitable for execution in a .emacs file."
(interactive "P")
(save-excursion
- (let* ((date (if arg
- (calendar-read-date t)
+ (let* ((date (if arg (calendar-read-date t)
(calendar-current-date)))
(displayed-month (extract-calendar-month date))
(displayed-year (extract-calendar-year date)))
(calendar-phases-of-moon))))
+(defvar date)
+
+;; To be called from list-sexp-diary-entries, where DATE is bound.
+
+;;;###diary-autoload
(defun diary-phases-of-moon (&optional mark)
-"Moon phases diary entry.
+ "Moon phases diary entry.
An optional parameter MARK specifies a face or single-character string to
use when highlighting the day in the calendar."
(let* ((index (* 4
-1900)))))
(phase (lunar-phase index)))
(while (calendar-date-compare phase (list date))
- (setq index (1+ index))
- (setq phase (lunar-phase index)))
+ (setq index (1+ index)
+ phase (lunar-phase index)))
(if (calendar-date-equal (car phase) date)
- (cons mark (concat (lunar-phase-name (car (cdr (cdr phase)))) " "
- (car (cdr phase)))))))
+ (cons mark (concat (lunar-phase-name (nth 2 phase)) " "
+ (cadr 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.
+;; 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)))
+ (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))))))
+ (floor (calendar-astro-to-absolute newJDE))))))
(/ calendar-time-zone 60.0 24.0))))
(defun lunar-new-moon-on-or-after (d)
The fractional part is the time of day.
The date and time are local time, including any daylight saving 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."
+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))))
+ (floor (calendar-astro-to-absolute 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))))))
+ (/ (calendar-day-number date) 365.25)))
+ (k (floor (* (- year 2000.0) 12.3685)))
+ (date (lunar-new-moon-time k))
+ (a-date (progn
+ (while (< date d)
+ (setq k (1+ k)
+ date (lunar-new-moon-time k)))
+ (calendar-astro-to-absolute 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))
+ (/ (cadr adj) 24.0)))))
(provide 'lunar)