procyberian/emacs
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fix sunrise and sunset calculation (bug#44237)

Browse source 
* lisp/calendar/solar.el (solar-moment): Use initial values for binary
search that won't end the loop prematurely and yield incorrect
answers.
* test/lisp/calendar/solar-tests.el: New file.
This commit is contained in:
Mattias Engdegård 2020-10-26 18:44:05 +01:00
parent f971a612a9
commit cde72637df
2 changed files with 44 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
lisp/calendar/solar.el
View file

@ -490,8 +490,8 @@ Uses binary search."
(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
(utmoment-old utmin) ; rise or set approximation
(utmoment utmax) ; rise or set approximation
(hut 0) ; sun height at utmoment
(t0 (car time))
(hmin (cadr (solar-horizontal-coordinates (list t0 utmin)

42
test/lisp/calendar/solar-tests.el Normal file
View file

@ -0,0 +1,42 @@
;;; solar-tests.el --- tests for solar.el -*- lexical-binding: t -*-
;; Copyright (C) 2020 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
(require 'ert)
(require 'solar)
(ert-deftest solar-sunrise-sunset ()
;; Bug#44237: wrong sunrise time on Dec 30 and 31, 2020 for Jaipur.
(let ((calendar-latitude 26.9)
(calendar-longitude 75.8)
(calendar-time-zone +330)
(calendar-standard-time-zone-name "IST")
(calendar-daylight-time-zone-name "IST")
(epsilon (/ 60.0))) ; Minute accuracy is good enough.
(let* ((sunrise-sunset (solar-sunrise-sunset '(12 30 2020)))
(sunrise (car (nth 0 sunrise-sunset)))
(sunset (car (nth 1 sunrise-sunset))))
(should (< (abs (- sunrise 7.27)) epsilon))
(should (< (abs (- sunset 17.72)) epsilon)))
(let* ((sunrise-sunset (solar-sunrise-sunset '(12 31 2020)))
(sunrise (car (nth 0 sunrise-sunset)))
(sunset (car (nth 1 sunrise-sunset))))
(should (< (abs (- sunrise 7.28)) epsilon))
(should (< (abs (- sunset 17.72)) epsilon)))))
(provide 'solar-tests)