Class: EphJpl::Ephemeris

Inherits:
Object
  • Object
show all
Defined in:
lib/eph_jpl/ephemeris.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(target, center, jd, bin, km = false) ⇒ Ephemeris

Returns a new instance of Ephemeris.



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# File 'lib/eph_jpl/ephemeris.rb', line 6

def initialize(target, center, jd, bin, km = false)
  @target, @center, @jd, @km = target, center, jd, km
  @target_name = Const::ASTRS[@target - 1]
  @center_name = Const::ASTRS[@center - 1]
  @unit = @target > 13 ? "rad, rad/day" : @km ? "km, km/sec" : "AU, AU/day"
  @bin = bin
  @list = get_list
end

Instance Attribute Details

#bin ⇒ Object (readonly)

Returns the value of attribute bin.



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# File 'lib/eph_jpl/ephemeris.rb', line 3

def bin
  @bin
end

#center ⇒ Object (readonly)

Returns the value of attribute center.



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# File 'lib/eph_jpl/ephemeris.rb', line 3

def center
  @center
end

#center_name ⇒ Object (readonly)

Returns the value of attribute center_name.



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# File 'lib/eph_jpl/ephemeris.rb', line 3

def center_name
  @center_name
end

#jd ⇒ Object (readonly)

Returns the value of attribute jd.



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# File 'lib/eph_jpl/ephemeris.rb', line 3

def jd
  @jd
end

#km ⇒ Object (readonly)

Returns the value of attribute km.



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# File 'lib/eph_jpl/ephemeris.rb', line 3

def km
  @km
end

#target ⇒ Object (readonly)

Returns the value of attribute target.



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# File 'lib/eph_jpl/ephemeris.rb', line 3

def target
  @target
end

#target_name ⇒ Object (readonly)

Returns the value of attribute target_name.



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# File 'lib/eph_jpl/ephemeris.rb', line 3

def target_name
  @target_name
end

#unit ⇒ Object (readonly)

Returns the value of attribute unit.



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# File 'lib/eph_jpl/ephemeris.rb', line 3

def unit
  @unit
end

Instance Method Details

#calc ⇒ Object 



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# File 'lib/eph_jpl/ephemeris.rb', line 15

def calc
  pvs     = Array.new(11).map { |a| Array.new(6, 0.0) }  # for position, velocity
  pvs_tmp = Array.new(13)      # Temporary array for position, velocity of target and center
  rrds    = Array.new(6, 0.0)  # for calculated data (difference between target and center)

  begin
    # Interpolate (11:Sun)
    pv_sun = interpolate(11)
    # Interpolate (1:Mercury - 10:Moon)
    0.upto(9) do |i|
      next if @list[i] == 0
      pvs[i] = interpolate(i + 1)
      next if i > 8
      next if Const::BARY
      pvs[i] = pvs[i].map.with_index do |pv, j|
        pv - pv_sun[j]
      end
    end
    # Interpolate (14:Nutation)
    if @list[10] > 0 && @bin[:ipts][11][1] > 0
      p_nut = interpolate(14)
    end
    # Interpolate (15:Libration）
    if @list[11] > 0 && @bin[:ipts][12][1] > 0
      pvs[10] = interpolate(15)
    end

    # Difference between target and center
    case
    when @target == 14
      rrds = p_nut if @bin[:ipts][11][1] > 0
    when @target == 15
      rrds = pvs[10] if @bin[:ipts][12][1] > 0
    else
      0.upto(9) { |i| pvs_tmp[i] = pvs[i] }
      pvs_tmp[10] = pv_sun            if [@target, @center].include?(11)
      pvs_tmp[11] = Array.new(6, 0.0) if [@target, @center].include?(12)
      pvs_tmp[12] = pvs[2]            if [@target, @center].include?(13)
      if @target * @center == 30 || @target + @center == 13
        pvs_tmp[2] = Array.new(6, 0.0)
      else
        pvs_tmp[2] = pvs[2].map.with_index do |pv, i|
          pv - pvs[9][i] / (1.0 + @bin[:emrat])
        end unless @list[2] == 0
        pvs_tmp[9] = pvs_tmp[2].map.with_index do |pv, i|
          pv + pvs[9][i]
        end unless @list[9] == 0
      end
      0.upto(5) do |i|
        rrds[i] = pvs_tmp[@target - 1][i] - pvs_tmp[@center - 1][i]
      end
    end
    return rrds
  rescue => e
    raise
  end
end