Class: Accumulators::Mean

Inherits:
Object
  • Object
show all
Defined in:
lib/accumulators/mean.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Mean

Returns a new instance of Mean.



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# File 'lib/accumulators/mean.rb', line 6

def initialize
  @count = 0
  @mean = 0.0
end

Instance Attribute Details

#count ⇒ Object (readonly)

Returns the value of attribute count.



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# File 'lib/accumulators/mean.rb', line 4

def count
  @count
end

#mean ⇒ Object (readonly)

Returns the value of attribute mean.



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# File 'lib/accumulators/mean.rb', line 4

def mean
  @mean
end

Instance Method Details

#add(rhs) ⇒ Object 



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# File 'lib/accumulators/mean.rb', line 11

def add(rhs)
  if rhs.is_a? Numeric
    value_to_add = rhs.to_f
    @mean = @mean + (value_to_add - @mean)/(@count + 1)
    @count += 1
  elsif rhs.is_a? Accumulators::Mean
    sum = @mean * @count
    rhs_sum = rhs.mean * rhs.count
    @count = @count + rhs.count
    @mean = (sum + rhs_sum) / @count
  else
    raise ArgumentError.new("You may not add #{rhs.class} to #{self.class}")
  end
end