[Emacs-diffs] Changes to emacs/lisp/calendar/solar.el

[Richard M. Stallman]

Index: emacs/lisp/calendar/solar.el
diff -c emacs/lisp/calendar/solar.el:1.41 emacs/lisp/calendar/solar.el:1.42
*** emacs/lisp/calendar/solar.el:1.41   Sun Jan 13 05:01:42 2002
--- emacs/lisp/calendar/solar.el        Wed Apr  3 09:33:57 2002
***************
*** 198,205 ****
     nil 
     "Sidereal time at Greenwich at midnight (universal time).")
  
! (defvar solar-spring-or-summer-season nil  
!   "T if spring or summer and nil otherwise.
  Needed for polar areas, in order to know whether the day lasts 0 or 24 
hours.")
  
  (defun solar-setup ()
--- 198,205 ----
     nil 
     "Sidereal time at Greenwich at midnight (universal time).")
  
! (defvar solar-northern-spring-or-summer-season nil
!   "T if northern spring or summer and nil otherwise.
  Needed for polar areas, in order to know whether the day lasts 0 or 24 
hours.")
  
  (defun solar-setup ()
***************
*** 298,305 ****
     (* (solar-sin-degrees obliquity)
        (solar-sin-degrees longitude))))
  
! (defun solar-sunrise-and-sunset (time latitude longitude)
!   "Sunrise, sunset and length of day. 
  Parameters are the midday TIME and the LATITUDE, LONGITUDE of the location.
  
  TIME is a pair with the first component being the number of Julian centuries
--- 298,305 ----
     (* (solar-sin-degrees obliquity)
        (solar-sin-degrees longitude))))
  
! (defun solar-sunrise-and-sunset (time latitude longitude height)
!   "Sunrise, sunset and length of day.
  Parameters are the midday TIME and the LATITUDE, LONGITUDE of the location.
  
  TIME is a pair with the first component being the number of Julian centuries
***************
*** 308,329 ****
  \(-0.040945 16), -0.040945 being the number of julian centuries elapsed 
between
  Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.
  
! Coordinates are included because this function is called with latitude=10
  degrees to find out if polar regions have 24 hours of sun or only night."
!   (let* ((rise-time (solar-moment -1 latitude longitude time))
!          (set-time (solar-moment 1 latitude longitude time))
           (day-length))
      (if (not (and rise-time set-time))
!         (if (or (and (> latitude 0) solar-spring-or-summer-season)
!                 (and (< latitude 0) (not solar-spring-or-summer-season)))
!           (setq day-length 0)
!           (setq day-length 24))
!         (setq day-length (- set-time rise-time)))
      (list (if rise-time (+ rise-time (/ calendar-time-zone 60.0)) nil)
            (if set-time (+ set-time (/ calendar-time-zone 60.0)) nil)
            day-length)))
  
! (defun solar-moment (direction latitude longitude time)
    "Sunrise/sunset at location.
  Sunrise if DIRECTION =-1 or sunset if =1 at LATITUDE, LONGITUDE, with midday
  being TIME.
--- 308,335 ----
  \(-0.040945 16), -0.040945 being the number of julian centuries elapsed 
between
  Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.
  
! HEIGHT is the angle the center of the sun has over the horizon for the contact
! we are trying to find. For sunrise and sunset, it is usually -0.61 degrees,
! accounting for the edge of the sun being on the horizon.
! 
! Coordinates are included because this function is called with latitude=1
  degrees to find out if polar regions have 24 hours of sun or only night."
!   (let* ((rise-time (solar-moment -1 latitude longitude time height))
!          (set-time (solar-moment 1 latitude longitude time height))
           (day-length))
      (if (not (and rise-time set-time))
!         (if (or (and (> latitude 0)
!                      solar-northern-spring-or-summer-season)
!                 (and (< latitude 0)
!                      (not solar-northern-spring-or-summer-season)))
!             (setq day-length 24)
!         (setq day-length 0))
!       (setq day-length (- set-time rise-time)))
      (list (if rise-time (+ rise-time (/ calendar-time-zone 60.0)) nil)
            (if set-time (+ set-time (/ calendar-time-zone 60.0)) nil)
            day-length)))
  
! (defun solar-moment (direction latitude longitude time height)
    "Sunrise/sunset at location.
  Sunrise if DIRECTION =-1 or sunset if =1 at LATITUDE, LONGITUDE, with midday
  being TIME.
***************
*** 334,374 ****
  \(-0.040945 16), -0.040945 being the number of julian centuries elapsed 
between
  Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.
  
  Uses binary search."
    (let* ((ut (car (cdr time)))
!          (possible 1) ; we assume that rise or set are possible
!          (utmin (+ ut (* direction 12.0))) 
           (utmax ut)    ; the time searched is between utmin and utmax
              ; utmin and utmax are in hours
           (utmoment-old 0.0)    ; rise or set approximation
           (utmoment 1.0) ; rise or set approximation
           (hut 0)         ; sun height at utmoment
           (t0 (car time))
!          (hmin (car (cdr 
!                (solar-horizontal-coordinates (list t0 utmin) 
                                                  latitude longitude t))))
!          (hmax (car (cdr 
!                (solar-horizontal-coordinates (list t0 utmax) 
                                                  latitude longitude t)))))
         ; -0.61 degrees is the height of the middle of the sun, when it rises
         ;   or sets.
!      (if (< hmin -0.61) 
!               (if (> hmax -0.61)
                    (while ;(< i 20) ; we perform a simple dichotomy
!                          ; (> (abs (+ hut 0.61)) epsilon)
                           (>= (abs (- utmoment utmoment-old))
                               (/ solar-error 60))
                      (setq utmoment-old utmoment)
                      (setq utmoment (/ (+ utmin utmax) 2))
!                     (setq hut (car (cdr 
!                                     (solar-horizontal-coordinates 
                                     (list t0 utmoment) latitude longitude t))))
!                     (if (< hut -0.61) (setq utmin utmoment))
!                     (if (> hut -0.61) (setq utmax utmoment))
                     )
!                 (setq possible 0)) ; the sun never rises
!                 (setq possible 0)) ; the sun never sets
!      (if (equal possible 0) nil utmoment)))
  
  (defun solar-time-string (time time-zone)
    "Printable form for decimal fraction TIME in TIME-ZONE.
--- 340,384 ----
  \(-0.040945 16), -0.040945 being the number of julian centuries elapsed 
between
  Jan 1, 2000 at 12 UT and November 28, 1995 at 0 UT.
  
+ HEIGHT is the angle the center of the sun has over the horizon for the contact
+ we are trying to find. For sunrise and sunset, it is usually -0.61 degrees,
+ accounting for the edge of the sun being on the horizon.
+ 
  Uses binary search."
    (let* ((ut (car (cdr time)))
!          (possible t) ; we assume that rise or set are possible
!          (utmin (+ ut (* direction 12.0)))
           (utmax ut)    ; the time searched is between utmin and utmax
              ; utmin and utmax are in hours
           (utmoment-old 0.0)    ; rise or set approximation
           (utmoment 1.0) ; rise or set approximation
           (hut 0)         ; sun height at utmoment
           (t0 (car time))
!          (hmin (car (cdr
!                (solar-horizontal-coordinates (list t0 utmin)
                                                  latitude longitude t))))
!          (hmax (car (cdr
!                (solar-horizontal-coordinates (list t0 utmax)
                                                  latitude longitude t)))))
         ; -0.61 degrees is the height of the middle of the sun, when it rises
         ;   or sets.
!      (if (< hmin height)
!               (if (> hmax height)
                    (while ;(< i 20) ; we perform a simple dichotomy
!                          ; (> (abs (- hut height)) epsilon)
                           (>= (abs (- utmoment utmoment-old))
                               (/ solar-error 60))
                      (setq utmoment-old utmoment)
                      (setq utmoment (/ (+ utmin utmax) 2))
!                     (setq hut (car (cdr
!                                     (solar-horizontal-coordinates
                                     (list t0 utmoment) latitude longitude t))))
!                     (if (< hut height) (setq utmin utmoment))
!                     (if (> hut height) (setq utmax utmoment))
                     )
!                 (setq possible nil)) ; the sun never rises
!                 (setq possible nil)) ; the sun never sets
!      (if (not possible) nil utmoment)))
  
  (defun solar-time-string (time time-zone)
    "Printable form for decimal fraction TIME in TIME-ZONE.
***************
*** 423,446 ****
           ; store the sidereal time at Greenwich at midnight of UT time.
           ; find if summer or winter slightly above the equator
           (equator-rise-set
!           (progn (setq solar-sidereal-time-greenwich-midnight 
                         (solar-sidereal-time t0))
!                  (solar-sunrise-and-sunset 
                    (list t0 (car (cdr exact-local-noon)))
!                   10.0
!                   (calendar-longitude))))
           ; store the spring/summer information,
           ; compute sunrise and sunset (two first components of rise-set).
           ; length of day is the third component (it is only the difference
           ; between sunset and sunrise when there is a sunset and a sunrise)
           (rise-set
            (progn
!             (setq solar-spring-or-summer-season 
!                   (if (> (car (cdr (cdr equator-rise-set))) 12) 1 0))
!             (solar-sunrise-and-sunset 
               (list t0 (car (cdr exact-local-noon)))
               (calendar-latitude)
!              (calendar-longitude))))
           (rise (car rise-set))
           (adj-rise (if rise (dst-adjust-time date rise) nil))
           (set (car (cdr rise-set)))
--- 433,456 ----
           ; store the sidereal time at Greenwich at midnight of UT time.
           ; find if summer or winter slightly above the equator
           (equator-rise-set
!           (progn (setq solar-sidereal-time-greenwich-midnight
                         (solar-sidereal-time t0))
!                  (solar-sunrise-and-sunset
                    (list t0 (car (cdr exact-local-noon)))
!                   1.0
!                   (calendar-longitude) 0)))
           ; store the spring/summer information,
           ; compute sunrise and sunset (two first components of rise-set).
           ; length of day is the third component (it is only the difference
           ; between sunset and sunrise when there is a sunset and a sunrise)
           (rise-set
            (progn
!             (setq solar-northern-spring-or-summer-season
!                   (if (> (car (cdr (cdr equator-rise-set))) 12) t nil))
!             (solar-sunrise-and-sunset
               (list t0 (car (cdr exact-local-noon)))
               (calendar-latitude)
!              (calendar-longitude) -0.61)))
           (rise (car rise-set))
           (adj-rise (if rise (dst-adjust-time date rise) nil))
           (set (car (cdr rise-set)))
***************
*** 904,909 ****
--- 914,925 ----
        (solar-setup))
    (solar-sunrise-sunset-string date))
  
+ (defcustom diary-sabbath-candles-minutes 18
+   "*Number of minutes before sunset for sabbath candle lighting."
+   :group 'diary
+   :type 'integer
+   :version "21.1")
+ 
  (defun diary-sabbath-candles ()
    "Local time of candle lighting diary entry--applies if date is a Friday.
  No diary entry if there is no sunset on that date."
***************
*** 911,918 ****
        (solar-setup))
    (if (= (% (calendar-absolute-from-gregorian date) 7) 5);;  Friday
        (let* ((sunset (car (cdr (solar-sunrise-sunset date))))
!                   (light (if sunset
!                         (cons (- (car sunset) (/ 18.0 60.0)) (cdr sunset)))))
          (if sunset
              (format "%s Sabbath candle lighting"
                      (apply 'solar-time-string light))))))
--- 927,936 ----
        (solar-setup))
    (if (= (% (calendar-absolute-from-gregorian date) 7) 5);;  Friday
        (let* ((sunset (car (cdr (solar-sunrise-sunset date))))
!              (light (if sunset
!                         (cons (- (car sunset)
!                                  (/ diary-sabbath-candles-minutes 60.0))
!                               (cdr sunset)))))
          (if sunset
              (format "%s Sabbath candle lighting"
                      (apply 'solar-time-string light))))))