Module: MeasureScaler::Prefixes

Included in:
Prefix
Defined in:
lib/measure_scaler/prefixes.rb

Constant Summary collapse

LIST =

en.wikipedia.org/wiki/Metric_prefix

["y", "z", "a", "f", "p", "n", "µ", "m", "", "k", "M", "G", "T", "P", "E", "Z", "Y"]
MAX_FACTOR = 
24
MIN_FACTOR = 
-24
STEP = 
3

Instance Method Summary collapse

Instance Method Details

#find_factor(symbol) ⇒ Object

Get the base-10 exponent related to the symbol Example: find_factor(“M”) # => 6 (million)



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# File 'lib/measure_scaler/prefixes.rb', line 12

def find_factor(symbol)
  valid?(symbol) ? (LIST.index(symbol)*STEP)+MIN_FACTOR : nil
end

#find_symbol(factor) ⇒ Object

Get the symbol related to base-10 passed The factor should be a multiple of 3, greater or equal to -24 and smaller or equal to 24 Example: find_symbol(-3) # => “m” (thousandth)



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# File 'lib/measure_scaler/prefixes.rb', line 20

def find_symbol(factor)
  return nil if factor%STEP!=0 || factor<MIN_FACTOR || factor>MAX_FACTOR
  LIST[(factor-MIN_FACTOR)/STEP]
end

#symbols_list ⇒ Object

Return the list of available symbols



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# File 'lib/measure_scaler/prefixes.rb', line 31

def symbols_list
  LIST
end

#valid?(symbol) ⇒ Boolean

Is a valid symbol?

Returns:

  • (Boolean) 


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# File 'lib/measure_scaler/prefixes.rb', line 26

def valid?(symbol)
  LIST.include?(symbol)
end