Class: Array

Inherits:
Object show all
Defined in:
lib/swak.rb

Instance Method Summary collapse

Instance Method Details

#argmax ⇒ Object 



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# File 'lib/swak.rb', line 114

def argmax
  max_i = 0
  max_val = self[max_i]

  self.each_with_index do |x, i|
    if x > max_val
      max_val = x
      max_i = i
    end
  end

  return max_i
end

#argmin ⇒ Object 



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# File 'lib/swak.rb', line 128

def argmin
  min_i = 0
  min_val = self[min_i]

  self.each_with_index do |x, i|
    if x < min_val
      min_val = x
      min_i = i
    end
  end

  return min_i
end

#avg ⇒ Object 



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# File 'lib/swak.rb', line 91

def avg
	return sum.to_f / self.length
end

#hist ⇒ Object 



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# File 'lib/swak.rb', line 65

def hist
	h = {}
	for item in self
		h[item] ||= 0
		h[item] += 1
	end
	return h
end

#mean ⇒ Object 



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# File 'lib/swak.rb', line 110

def mean
	return self.avg
end

#shuffle ⇒ Object 



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# File 'lib/swak.rb', line 79

def shuffle
	return dup().sort_by {rand}
end

#shuffle! ⇒ Object 



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# File 'lib/swak.rb', line 74

def shuffle!
	sort_by {rand}
	return self
end

#stddev ⇒ Object 



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# File 'lib/swak.rb', line 106

def stddev
	return Math.sqrt(self.variance())
end

#sum ⇒ Object 



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# File 'lib/swak.rb', line 83

def sum
	total = 0
	for item in self
		total += item
	end
	return total
end

#variance ⇒ Object

Sample variance



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# File 'lib/swak.rb', line 96

def variance
	average = avg()
	variance = 0
	for item in self
		diff = item - average
		variance += diff * diff
	end
	return variance / (self.length - 1)
end