Ruby script to convert celestial coordinates.

coord_conversion.rb

#! /usr/local/bin/ruby
# coding: utf-8
#---------------------------------------------------------------------------------
#= 赤道・黄道座標変換
#
# date          name            version
# 2016.08.29    mk-mode.com     1.00 新規作成
#
# Copyright(C) 2016 mk-mode.com All Rights Reserved.
#---------------------------------------------------------------------------------
#++
require "mk_coord"

class CoordConversion
  # 黄道傾斜角(単位: rad)
  # (Math::PI は MkCoord::Const::PI と置き換えてもよい)
  EPS = 23.43929 * Math::PI / 180.0
  # 元の赤道直交座標
  POS = [
     0.99443659220700997281,
    -0.03816291768957833647,
    -0.01655177670960058384
  ]  # <= ある日の地球重心から見た太陽重心の位置(単位: AU)

  def exec
    puts "元の赤道直交座標:\n  #{POS}"
    rect_ec = MkCoord.rect_eq2ec(POS, EPS)
    puts "黄道直交座標に変換:\n  #{rect_ec}"
    rect_eq = MkCoord.rect_ec2eq(rect_ec, EPS)
    puts "赤道直交座標に戻す:\n  #{rect_eq}"
    *pol_eq, r = MkCoord.rect2pol(rect_eq)
    puts "赤道極座標に変換:\n  #{pol_eq[0, 2]} (R = #{r})"
    pol_ec = MkCoord.pol_eq2ec(pol_eq[0, 2], EPS)
    puts "黄道極座標に変換:\n  #{pol_ec[0, 2]}"
    pol_eq = MkCoord.pol_ec2eq(pol_ec, EPS)
    puts "赤道極座標に戻す:\n  #{pol_eq[0, 2]}"
    rect_eq = MkCoord.pol2rect(pol_eq[0, 2], r)
    puts "赤道直交座標に戻す:\n  #{rect_eq}"
  rescue => e
    puts "[#{e.class}] #{e.message}"
    e.backtrace.each { |tr| $stderr.puts "\t#{tr}" }
    exit 1
  end
end

CoordConversion.new.exec if __FILE__ == $0