Class: PhotoUtils::Illuminance

Inherits:
Value show all
Defined in:
lib/photo_utils/illuminance.rb

Constant Summary collapse

N = 
2 ** Rational(-7, 4)
C = 
224
NC = 
N * C

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Value

#<=>, #==, #decr, #incr, #initialize

Methods inherited from Float

#format, #prec

Constructor Details

This class inherits a constructor from PhotoUtils::Value

Class Method Details

.new_from_lux(lux) ⇒ Object

amount specified in lux



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# File 'lib/photo_utils/illuminance.rb', line 11

def self.new_from_lux(lux)
  new(lux)
end

.new_from_v(v) ⇒ Object 



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# File 'lib/photo_utils/illuminance.rb', line 15

def self.new_from_v(v)
  new((2 ** v.to_f) * NC)
end

Instance Method Details

#format_lux ⇒ Object 



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# File 'lib/photo_utils/illuminance.rb', line 27

def format_lux
  to_lux.format(10) + ' lux'
end

#format_value ⇒ Object 



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# File 'lib/photo_utils/illuminance.rb', line 31

def format_value
  "Iv:#{to_v.format(10)}"
end

#to_lux ⇒ Object 



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# File 'lib/photo_utils/illuminance.rb', line 23

def to_lux
  to_f
end

#to_s(format = :lux) ⇒ Object 



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# File 'lib/photo_utils/illuminance.rb', line 35

def to_s(format=:lux)
  case format
  when :lux
    format_lux
  when :value
    format_value
  else
    raise "Unknown format: #{format.inspect}"
  end
end

#to_v ⇒ Object 



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# File 'lib/photo_utils/illuminance.rb', line 19

def to_v
  Math.log2(self / NC)
end