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author | Glenn Morris <rgm@gnu.org> | 2008-03-08 21:27:23 +0000 |
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committer | Glenn Morris <rgm@gnu.org> | 2008-03-08 21:27:23 +0000 |
commit | 53bee0c9ea662e4e7a14f04680a0674947586f13 (patch) | |
tree | 72ed4578edc4b8052ce255d01ff2698012f97f42 /lisp/calendar/solar.el | |
parent | 754c5007639b4dd81ca1781f03f243fa456ef63e (diff) | |
download | emacs-53bee0c9ea662e4e7a14f04680a0674947586f13.tar.gz |
Formatting changes only.
Diffstat (limited to 'lisp/calendar/solar.el')
-rw-r--r-- | lisp/calendar/solar.el | 92 |
1 files changed, 46 insertions, 46 deletions
diff --git a/lisp/calendar/solar.el b/lisp/calendar/solar.el index 71c22995593..ecb5321c5a7 100644 --- a/lisp/calendar/solar.el +++ b/lisp/calendar/solar.el @@ -348,13 +348,13 @@ 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 + (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 + (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) @@ -362,12 +362,12 @@ Uses binary search." (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. + ;; -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) + (while ;;; (< i 20) ; we perform a simple dichotomy + ;;; (> (abs (- hut height)) epsilon) (>= (abs (- utmoment utmoment-old)) (/ solar-error 60)) (setq utmoment-old utmoment) @@ -378,8 +378,8 @@ Uses binary search." (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 + (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) @@ -428,12 +428,12 @@ local date. The second component of date should be an integer." "List of *local* times of sunrise, sunset, and daylight on Gregorian DATE. Corresponding value is nil if there is no sunrise/sunset." - (let* (; first, get the exact moment of local noon. - (exact-local-noon (solar-exact-local-noon date)) - ; get the time from the 2000 epoch. + ;; First, get the exact moment of local noon. + (let* ((exact-local-noon (solar-exact-local-noon date)) + ;; Get the time from the 2000 epoch. (t0 (solar-julian-ut-centuries (car exact-local-noon))) - ; store the sidereal time at Greenwich at midnight of UT time. - ; find if summer or winter slightly above the equator + ;; 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)) @@ -441,10 +441,10 @@ Corresponding value is nil if there is no sunrise/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) + ;; 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 @@ -519,7 +519,7 @@ calendar-time-zone are used to interpret local time." (next (mod (* l (1+ (floor (/ start-long l)))) 360)) (end (+ d (* (/ l 360.0) 400))) (end-long (solar-longitude end))) - (while ;; bisection search for nearest minute + (while ; bisection search for nearest minute (< 0.00001 (- end start)) ;; start <= d < end ;; start-long <= next < end-long when next != 0 @@ -551,8 +551,8 @@ The azimuth is given in degrees as well as the height (between -180 and 180)." (ec (solar-equatorial-coordinates time for-sunrise-sunset)) (st (+ solar-sidereal-time-greenwich-midnight (* ut 1.00273790935))) + ;; Hour angle (in degrees). (ah (- (* st 15) (* 15 (car ec)) (* -1 (calendar-longitude)))) - ; hour angle (in degrees) (de (car (cdr ec))) (azimuth (solar-atn2 (- (* (solar-cosine-degrees ah) (solar-sin-degrees latitude)) @@ -589,14 +589,14 @@ since January 1st, 2000, at 12 ET." (* 36000.76983 time) (* 0.0003032 time time))) ; sun mean longitude (ml (+ 218.3165 - (* 481267.8813 time))) ; moon mean longitude + (* 481267.8813 time))) ; moon mean longitude (m (+ 357.52910 (* 35999.05030 time) (* -0.0001559 time time) (* -0.00000048 time time time))) ; sun mean anomaly (i (+ 23.43929111 (* -0.013004167 time) (* -0.00000016389 time time) - (* 0.0000005036 time time time))); mean inclination + (* 0.0000005036 time time time))) ; mean inclination (c (+ (* (+ 1.914600 (* -0.004817 time) (* -0.000014 time time)) @@ -605,17 +605,17 @@ since January 1st, 2000, at 12 ET." (solar-sin-degrees (* 2 m))) (* 0.000290 (solar-sin-degrees (* 3 m))))) ; center equation - (L (+ l c)) ; total longitude + (L (+ l c)) ; total longitude + ;; Longitude of moon's ascending node on the ecliptic. (omega (+ 125.04 - (* -1934.136 time))) ; longitude of moon's ascending node - ; on the ecliptic + (* -1934.136 time))) + ;; nut = nutation in longitude, measured in seconds of angle. (nut (if (not for-sunrise-sunset) (+ (* -17.20 (solar-sin-degrees omega)) (* -1.32 (solar-sin-degrees (* 2 l))) (* -0.23 (solar-sin-degrees (* 2 ml))) (* 0.21 (solar-sin-degrees (* 2 omega)))) nil)) - ; nut = nutation in longitude, measured in seconds of angle. (ecc (if (not for-sunrise-sunset) (+ 0.016708617 (* -0.000042037 time) @@ -629,6 +629,7 @@ since January 1st, 2000, at 12 ET." (* (solar-tangent-degrees (/ i 2)) (solar-tangent-degrees (/ i 2))) nil)) + ;; Equation of time, in hours. (time-eq (if (not for-sunrise-sunset) (/ (* 12 (+ (* y (solar-sin-degrees (* 2 l))) (* -2 ecc (solar-sin-degrees m)) @@ -638,7 +639,6 @@ since January 1st, 2000, at 12 ET." (* -1.25 ecc ecc (solar-sin-degrees (* 2 m))))) 3.1415926535) nil))) - ; equation of time, in hours (list app i time-eq nut))) (defconst solar-data-list @@ -702,13 +702,13 @@ calendar-daylight-savings-starts-time, calendar-daylight-savings-ends, calendar-daylight-savings-ends-time, calendar-daylight-time-offset, and calendar-time-zone are used to interpret local time." (let* ((a-d (calendar-absolute-from-astro d)) - ;; get Universal Time + ;; Get Universal Time. (date (calendar-astro-from-absolute (- a-d (if (dst-in-effect a-d) (/ calendar-daylight-time-offset 24.0 60.0) 0) (/ calendar-time-zone 60.0 24.0)))) - ;; get Ephemeris Time + ;; Get Ephemeris Time. (date (+ date (solar-ephemeris-correction (extract-calendar-year (calendar-gregorian-from-absolute @@ -808,7 +808,7 @@ T0 must correspond to 0 hours UT." (et (solar-ephemeris-time (list t0 0.0))) (nut-i (solar-ecliptic-coordinates et nil)) (nut (car (cdr (cdr (cdr nut-i))))) ; nutation - (i (car (cdr nut-i)))) ; inclination + (i (car (cdr nut-i)))) ; inclination (mod (+ (mod (+ mean-sid-time (/ (/ (* nut (solar-cosine-degrees i)) 15) 3600)) 24.0) 24.0) @@ -924,7 +924,7 @@ An optional parameter MARK specifies a face or single-character string to use when highlighting the day in the calendar." (if (not (and calendar-latitude calendar-longitude calendar-time-zone)) (solar-setup)) - (if (= (% (calendar-absolute-from-gregorian date) 7) 5);; Friday + (if (= (% (calendar-absolute-from-gregorian date) 7) 5) ; Friday (let* ((sunset (car (cdr (solar-sunrise-sunset date)))) (light (if sunset (cons (- (car sunset) @@ -935,7 +935,7 @@ use when highlighting the day in the calendar." (format "%s Sabbath candle lighting" (apply 'solar-time-string light))))))) -; from Meeus, 1991, page 167 +;; From Meeus, 1991, page 167. (defconst solar-seasons-data '((485 324.96 1934.136) (203 337.23 32964.467) @@ -980,8 +980,8 @@ Accurate to less than a minute between 1951 and 2050." (car (cdr x)))))) solar-seasons-data))) (JDE (+ JDE0 (/ (* 0.00001 S) Delta-lambda))) + ;; Ephemeris time correction. (correction (+ 102.3 (* 123.5 T) (* 32.5 T T))) - ; ephemeris time correction (JD (- JDE (/ correction 86400))) (date (calendar-gregorian-from-absolute (floor (- JD 1721424.5)))) (time (- (- JD 0.5) (floor (- JD 0.5)))) @@ -990,14 +990,14 @@ Accurate to less than a minute between 1951 and 2050." (/ (/ calendar-time-zone 60.0) 24.0)) (car (cdr (cdr date)))))) -; from Meeus, 1991, page 166 +;; From Meeus, 1991, page 166. (defun solar-mean-equinoxes/solstices (k year) "Julian day of mean equinox/solstice K for YEAR. K=0, spring equinox; K=1, summer solstice; K=2, fall equinox; K=3, winter solstice. These formulas are only to be used between 1000 BC and 3000 AD." (let ((y (/ year 1000.0)) (z (/ (- year 2000) 1000.0))) - (if (< year 1000) ; actually between -1000 and 1000 + (if (< year 1000) ; actually between -1000 and 1000 (cond ((equal k 0) (+ 1721139.29189 (* 365242.13740 y) (* 0.06134 y y) @@ -1018,7 +1018,7 @@ solstice. These formulas are only to be used between 1000 BC and 3000 AD." (* -0.00769 y y) (* -0.00933 y y y) (* -0.00006 y y y y)))) - ; actually between 1000 and 3000 + ; actually between 1000 and 3000 (cond ((equal k 0) (+ 2451623.80984 (* 365242.37404 z) (* 0.05169 z z) @@ -1064,13 +1064,13 @@ Requires floating point." (+ (car (cdr (car adj)) ) (/ (car (cdr adj)) 24.0)) (car (cdr (cdr (car adj)))))) - ; The following is nearly as accurate, but not quite: - ;(d0 (solar-date-next-longitude - ; (calendar-astro-from-absolute - ; (calendar-absolute-from-gregorian - ; (list (+ 3 (* k 3)) 15 y))) - ; 90)) - ;(abs-day (calendar-absolute-from-astro d))) + ;; The following is nearly as accurate, but not quite: + ;; (d0 (solar-date-next-longitude + ;; (calendar-astro-from-absolute + ;; (calendar-absolute-from-gregorian + ;; (list (+ 3 (* k 3)) 15 y))) + ;; 90)) + ;; (abs-day (calendar-absolute-from-astro d))) (abs-day (calendar-absolute-from-gregorian d))) (list (list (calendar-gregorian-from-absolute (floor abs-day)) |