Class: TimeStep::Pair

Inherits:
Object
  • Object
show all
Defined in:
lib/timesteps/timesteppair.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(from, to, calendar: "standard", bc: false) ⇒ Pair

Constructs the object.

The ‘from` and `to` arguments are either TimeStep or a string representing the time step definition (“<INTERVAL> since <TIME>”). If a string representing the time step definition is given as an argument `from` or `to`, the options `calendar` and `bc` are used to construct TimeStep. The option `calendar` specifies the calendar for datetime calculation. The option `bc` is a flag whether AD/BC or EC when parsing timestamp for negative year.

Parameters:

  • from (TimeStep, String)
  • to (TimeStep, String)
  • calendar (Hash) (defaults to: "standard") —

    a customizable set of options

  • bc (Hash) (defaults to: false) —

    a customizable set of options

Options Hash (calendar:):

Options Hash (bc:):

  • (Boolean) 


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# File 'lib/timesteps/timesteppair.rb', line 22

def initialize (from, to, calendar: "standard", bc: false)

  case from
  when String
    @from = TimeStep.new(from, calendar: calendar, bc: bc)
  when TimeStep
    @from = from
  else
    raise "first argument should be TimeStep or string"
  end
          
  case to
  when String
    @to = TimeStep.new(to, calendar: calendar, bc: bc)
  when TimeStep
    @to = to
  else
    raise "second argument should be TimeStep or string"
  end

  @from_origin = @from.origin
  @to_origin   = @to.origin
      
  @from_interval = @from.interval
  @to_interval   = @to.interval

  @from_symbol   = @from.symbol
  @to_symbol     = @to.symbol

  if @from_symbol == :years or @from_symbol == :months or
     @to_symbol == :years or @to_symbol == :months
    @numeric_conversion = false      
  else
    @numeric_conversion = true
  end

  @difference = ( (@from_origin.jd + @from_origin.fraction - @from_origin.offset) - 
                  (@to_origin.jd   + @to_origin.fraction - @to_origin.offset) ) * 86400
end

Instance Attribute Details

#difference ⇒ Object (readonly)

Returns the value of attribute difference.



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# File 'lib/timesteps/timesteppair.rb', line 62

def difference
  @difference
end

#from ⇒ Object (readonly)

Returns the value of attribute from.



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# File 'lib/timesteps/timesteppair.rb', line 62

def from
  @from
end

#to ⇒ Object (readonly)

Returns the value of attribute to.



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# File 'lib/timesteps/timesteppair.rb', line 62

def to
  @to
end

Instance Method Details

#==(other) ⇒ Boolean

Returns true if other has same contents of ‘from` and `to` as self has.

Returns:

  • (Boolean) 


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# File 'lib/timesteps/timesteppair.rb', line 71

def == (other)
  return @from == other.from && 
         @to == other.to 
end

#forward(*indices, &block) ⇒ Object Also known as: [] 



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# File 'lib/timesteps/timesteppair.rb', line 80

def forward (*indices, &block)
  if indices.size == 1    
    index = indices.first.to_r
    if @numeric_conversion
      value = (index*@from_interval + @difference).quo(@to_interval)
    else
      case @from_symbol
      when :years, :months
        target = @from.time_at(index)
      else
        target = @from_origin + index*(@from_interval.quo(86400))
      end
      case @to_symbol
      when :years        
        value = target.difference_in_years(@to_origin).quo(@to.numeric)
      when :months
        value = target.difference_in_months(@to_origin).quo(@to.numeric)
      else
        value = (target.ajd - @to_origin.ajd).quo(@to_interval)
      end
    end
    value = value.to_i if value.denominator == 1
    if block
      return block[value]
    else
      return value
    end
  else
    if block
      return indices.map { |index| block[forward(index)] }
    else
      return indices.map { |index| forward(index) }
    end
  end
end

#forward_time(index) ⇒ Object 



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# File 'lib/timesteps/timesteppair.rb', line 118

def forward_time (index)
  if @numeric_conversion
    return @to.time_at((index*@from_interval + @difference).quo(@to_interval))
  else
    case @from_symbol
    when :years, :months
      target = @from.time_at(index)
    else
      target = @from_origin + index*(@from_interval.quo(86400))
    end
    case @to_symbol
    when :years
      index = (target.year - @from_origin.year).quo(@to.numeric)
    when :months
      ms = 12*(target.year - @from_origin.year)
      ms += target.month - @from_origin.month
      index = ms.quo(@to.numeric)
    else
      index = (target.ajd - @from_origin.ajd).quo(@to_interval)
    end
    return @to.time_at(index)
  end      
end

#inspect ⇒ Object 



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# File 'lib/timesteps/timesteppair.rb', line 64

def inspect
  "#<TimeStep::Pair from='#{from.inspect}' to='#{to.inspect}'>"
end

#inverse(*indices, &block) ⇒ Object 



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# File 'lib/timesteps/timesteppair.rb', line 142

def inverse (*indices, &block)
  if indices.size == 1    
    index = indices.first.to_r
    if @numeric_conversion
      value = (index*@to_interval - @difference).quo(@from_interval)
    else
      case @to_symbol
      when :years, :months
        target = @to.time_at(index)
      else
        target = @to_origin + index*(@to_interval.quo(86400))
      end
      case @from_symbol
      when :years        
        value = target.difference_in_years(@from_origin).quo(@from.numeric)
      when :months
        value = target.difference_in_months(@from_origin).quo(@from.numeric)
      else
        value = (target.ajd - @from_origin.ajd).quo(@from_interval)
      end
      if block
        return block[value]
      else
        return value
      end
    end
  else
    if block
      return indices.map { |index| block[inverse(index)] }
    else
      return indices.map { |index| inverse(index) }
    end
  end
end

#inverse_time(index) ⇒ Object 



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# File 'lib/timesteps/timesteppair.rb', line 178

def inverse_time (index)
  if @numeric_conversion
    return @from.time_at((index*@to_interval - @difference).quo(@from_interval))
  else
    case @to_symbol
    when :years, :months
      target = @to.time_at(index)
    else
      target = @to_origin + index*(@to_interval.quo(86400))
    end
    case @from_symbol
    when :years
      index = (target.year - @to_origin.year).quo(@from.numeric)
    when :months
      ms = 12*(target.year - @to_origin.year)
      ms += target.month - @to_origin.month
      index = ms.quo(@from.numeric)
    else
      index = (target.ajd - @to_origin.ajd).quo(@from_interval)
    end
    return @from.time_at(index)
  end
end

#time_at(*indices) ⇒ Object 



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# File 'lib/timesteps/timesteppair.rb', line 76

def time_at (*indices)
  @from.time_at(*indices)
end