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| # | |
| # Lunar/Moon phases ruby class | |
| # | |
| # Code is based upon Bradley E. Schaefer''s moon phase algorithm. | |
| # Ruby version based on JavaScript Phase Calculator by Stephen R. Schmitt | |
| class Moon | |
| attr_reader :epoch, :phase, :days, :icon, :dist, :ll, :emoji | |
| # Return the current (or input a date) moon. | |
| # Moon.new | |
| # Moon.new(some_day) | |
| # | |
| # Methods available: | |
| # phase => Phase of the moon as a sym | |
| # days => Moon days | |
| # icon => An integer from 0 to 29 | |
| # dist => Distance in earth radii | |
| # ll => Moon ecliptic lat/lon | |
| # | |
| def initialize(epoch=Time.now) | |
| @epoch = epoch | |
| do_calc | |
| end | |
| private | |
| def calc_phase(p) | |
| case p | |
| when 0 then :new | |
| when 1..6 then :waxing_crescent | |
| when 7..9 then :first_quarter | |
| when 10..12 then :waxing_gibbous | |
| when 13..16 then :full | |
| when 17..20 then :waning_gibbous | |
| when 21..24 then :last_quarter | |
| when 25..28 then :waning_crescent | |
| else :new | |
| end | |
| end | |
| def calc_emoji(p) | |
| case p | |
| when 0 then "🌑" | |
| when 1..6 then "🌒" | |
| when 7..9 then "🌓" | |
| when 10..12 then "🌔" | |
| when 13..16 then "🌕" | |
| when 17..20 then "🌖" | |
| when 21..24 then "🌗" | |
| when 25..28 then "🌘" | |
| else "🌑" | |
| end | |
| end | |
| def calc_coords(inter, phase) | |
| phase = phase * 2 * Math::PI | |
| dp = 2 * Math::PI * normalize((inter - 2451562.2 ) / 27.55454988) | |
| @dist = 60.4 - 3.3 * Math.cos(dp) - 0.6 * Math.cos(2 * phase - dp) - 0.5 * Math.cos(2 * phase) | |
| np = 2 * Math::PI * normalize((inter - 2451565.2) / 27.212220817) | |
| la = 5.1 * Math.sin(np) | |
| rp = normalize((inter - 2451555.8 ) / 27.321582241) | |
| lo = 360 * rp + 6.3 * Math.sin(dp) + 1.3 * Math.sin(2 * phase - dp) + 0.7 * Math.sin(2 * phase) | |
| @ll = [la, lo] | |
| end | |
| def do_calc | |
| c_phase = 29.530588853 | |
| t_year = @epoch.year - ((12 - @epoch.month)/10).to_i | |
| t_month = (@epoch.month + 9) % 12 | |
| t1 = (365.25 * (t_year + 4712)).to_i | |
| t2 = (30.6 * t_month + 0.5).to_i | |
| t3 = (((t_year / 100.0) + 49.0) * 0.75).to_i - 38 | |
| inter = t1 + t2 + @epoch.day + 59 | |
| inter -= t3 if inter > 2299160 | |
| phase = normalize((inter - 2451550.1) / c_phase) | |
| res = phase * c_phase; | |
| @days = (res * 100).to_i / 100 | |
| @icon = res.to_i % 30 | |
| @phase = calc_phase(@icon) | |
| @emoji = calc_emoji(@icon) | |
| calc_coords(inter, phase) | |
| end | |
| def normalize(x) | |
| x %= 1 | |
| x += 1 if x < 0 | |
| x | |
| end | |
| end |
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Added emoji symbol