23.01.2021, 12:48
You don't have in "Common functions" rscalc function. I've copied it from my LM (I don't know why, maybe it is not included in backup):
Code:
-- sunrise / sunset calculation
function rscalc(latitude, longitude, when)
local pi = math.pi
local doublepi = pi * 2
local rads = pi / 180.0
local TZ = function(when)
local ts = os.time(when)
local utcdate, localdate = os.date('!*t', ts), os.date('*t', ts)
localdate.isdst = false
local diff = os.time(localdate) - os.time(utcdate)
return math.floor(diff / 60) / 60
end
local range = function(x)
local a = x / doublepi
local b = doublepi * (a - math.floor(a))
return b < 0 and (doublepi + b) or b
end
when = when or os.date('*t')
local y2k = { year = 2000, month = 1, day = 1 }
local y2kdays = os.time(when) - os.time(y2k)
y2kdays = math.ceil(y2kdays / 86400)
local meanlongitude = range(280.461 * rads + 0.9856474 * rads * y2kdays)
local meananomaly = range(357.528 * rads + 0.9856003 * rads * y2kdays)
local lambda = range(meanlongitude + 1.915 * rads * math.sin(meananomaly) + rads / 50 * math.sin(2 * meananomaly))
local obliq = 23.439 * rads - y2kdays * rads / 2500000
local alpha = math.atan2(math.cos(obliq) * math.sin(lambda), math.cos(lambda))
local declination = math.asin(math.sin(obliq) * math.sin(lambda))
local LL = meanlongitude - alpha
if meanlongitude < pi then
LL = LL + doublepi
end
local dfo = pi / 216.45
if latitude < 0 then
dfo = -dfo
end
local fo = math.min(math.tan(declination + dfo) * math.tan(latitude * rads), 1)
local ha = 12 * math.asin(fo) / pi + 6
local timezone = TZ(when)
local equation = 12 + timezone + 24 * (1 - LL / doublepi) - longitude / 15
local sunrise, sunset = equation - ha, equation + ha
if sunrise > 24 then
sunrise = sunrise - 24
end
if sunset > 24 then
sunset = sunset - 24
end
return math.floor(sunrise * 60), math.ceil(sunset * 60)
end
Done is better than perfect