Class: FinancialMath::ArithmeticProgression

Inherits:
Object
  • Object
show all
Defined in:
lib/financial_math/arithmetic_progression.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args) ⇒ ArithmeticProgression

Returns a new instance of ArithmeticProgression.



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# File 'lib/financial_math/arithmetic_progression.rb', line 5

def initialize(args)
  @distance = args.fetch(:distance, 1)
  @times = args.fetch(:times, 1)
  @initial_value = args.fetch(:initial_value, 0)
end

Instance Attribute Details

#distance ⇒ Object (readonly)

Returns the value of attribute distance.



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# File 'lib/financial_math/arithmetic_progression.rb', line 3

def distance
  @distance
end

#initial_value ⇒ Object (readonly)

Returns the value of attribute initial_value.



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# File 'lib/financial_math/arithmetic_progression.rb', line 3

def initial_value
  @initial_value
end

#times ⇒ Object (readonly)

Returns the value of attribute times.



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# File 'lib/financial_math/arithmetic_progression.rb', line 3

def times
  @times
end

Instance Method Details

#last_item ⇒ Object 



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# File 'lib/financial_math/arithmetic_progression.rb', line 11

def last_item
  (initial_value + (times - 1.0) * distance).round(2)
end

#sum ⇒ Object 



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# File 'lib/financial_math/arithmetic_progression.rb', line 15

def sum
  (times / 2.0 * (initial_value + last_item)).round(2)
end