Class: SimpleMetarParser::Wind

Inherits:
Base
  • Object
show all
Defined in:
lib/simple_metar_parser/metar/wind.rb

Constant Summary collapse

KNOTS_TO_METERS_PER_SECOND = 
1.85 / 3.6
KILOMETERS_PER_HOUR_TO_METERS_PER_SECOND = 
1.0 / 3.6

Instance Attribute Summary collapse

Attributes inherited from Base

#parent

Instance Method Summary collapse

Methods inherited from Base

#initialize

Constructor Details

This class inherits a constructor from SimpleMetarParser::Base

Instance Attribute Details

#wind ⇒ Object (readonly) Also known as: wind_speed

Wind speed in meters per second



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# File 'lib/simple_metar_parser/metar/wind.rb', line 106

def wind
  @wind
end

#wind_direction ⇒ Object (readonly)

Direction of wind



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# File 'lib/simple_metar_parser/metar/wind.rb', line 110

def wind_direction
  @wind_direction
end

Instance Method Details

#decode_split(s) ⇒ Object 



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# File 'lib/simple_metar_parser/metar/wind.rb', line 14

def decode_split(s)
  decode_wind(s)
  decode_wind_variable(s)
end

#decode_wind(s) ⇒ Object

Wind parameters in meters per second



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# File 'lib/simple_metar_parser/metar/wind.rb', line 24

def decode_wind(s)

  if s =~ /(\d{3})(\d{2})G?(\d{2})?(KT|MPS|KMH)/
    # different units
    wind = case $4
             when "KT" then
               $2.to_f * KNOTS_TO_METERS_PER_SECOND
             when "MPS" then
               $2.to_f
             when "KMH" then
               $2.to_f * KILOMETERS_PER_HOUR_TO_METERS_PER_SECOND
             else
               nil
           end

    wind_max = case $4
                 when "KT" then
                   $3.to_f * KNOTS_TO_METERS_PER_SECOND
                 when "MPS" then
                   $3.to_f
                 when "KMH" then
                   $3.to_f * KILOMETERS_PER_HOUR_TO_METERS_PER_SECOND
                 else
                   nil
               end

    # wind_max is not less than normal wind
    if wind_max < wind or wind_max.nil?
      wind_max = wind
    end

    @winds << {
      :wind => wind,
      :wind_max => wind_max,
      :wind_direction => $1.to_i
    }
  end

  # variable/unknown direction
  if s =~ /VRB(\d{2})(KT|MPS|KMH)/
    wind = case $2
             when "KT" then
               $1.to_f * KNOTS_TO_METERS_PER_SECOND
             when "MPS" then
               $1.to_f
             when "KMH" then
               $1.to_f * KILOMETERS_PER_HOUR_TO_METERS_PER_SECOND
             else
               nil
           end

    @winds << {
      :wind => wind
    }

  end
end

#decode_wind_variable(s) ⇒ Object

Variable wind direction



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# File 'lib/simple_metar_parser/metar/wind.rb', line 83

def decode_wind_variable(s)
  if s =~ /(\d{3})V(\d{3})/
    @winds_variable_directions << {
      :wind_variable_direction_from => $1.to_i,
      :wind_variable_direction_to => $2.to_i,
      :wind_direction => ($1.to_i + $2.to_i) / 2,
      :wind_variable => true
    }
  end
end

#direction ⇒ Object

Wind direction



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# File 'lib/simple_metar_parser/metar/wind.rb', line 140

def direction
  self.wind_direction
end

#kmh ⇒ Object

Kilometers per hour



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# File 'lib/simple_metar_parser/metar/wind.rb', line 130

def kmh
  self.wind_speed_kmh
end

#knots ⇒ Object

Knots



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# File 'lib/simple_metar_parser/metar/wind.rb', line 135

def knots
  self.wind_speed_knots
end

#mps ⇒ Object

Meters per second



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# File 'lib/simple_metar_parser/metar/wind.rb', line 125

def mps
  self.wind
end

#post_process ⇒ Object 



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# File 'lib/simple_metar_parser/metar/wind.rb', line 19

def post_process
  recalculate_winds
end

#recalculate_winds ⇒ Object

Calculate wind parameters, some metar string has multiple winds recorded



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# File 'lib/simple_metar_parser/metar/wind.rb', line 95

def recalculate_winds
  wind_sum = @winds.collect { |w| w[:wind] }.inject(0) { |b, i| b + i }
  @wind = wind_sum.to_f / @winds.size
  if @winds.size == 1
    @wind_direction = @winds.first[:wind_direction]
  else
    @wind_direction = nil
  end
end

#reset ⇒ Object 



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# File 'lib/simple_metar_parser/metar/wind.rb', line 6

def reset
  @winds = Array.new
  @winds_variable_directions = Array.new
end

#wind_speed_kmh ⇒ Object

Wind speed in KM/H



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# File 'lib/simple_metar_parser/metar/wind.rb', line 119

def wind_speed_kmh
  return self.wind if self.wind.nil?
  return self.wind / KILOMETERS_PER_HOUR_TO_METERS_PER_SECOND
end

#wind_speed_knots ⇒ Object

Wind speed in knots



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# File 'lib/simple_metar_parser/metar/wind.rb', line 113

def wind_speed_knots
  return self.wind if self.wind.nil?
  return self.wind / KNOTS_TO_METERS_PER_SECOND
end