Module: MM::Deltas

Defined in:
lib/mm/deltas.rb

Class Method Summary collapse

Class Method Details

.abs(n) ⇒ Object 



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# File 'lib/mm/deltas.rb', line 3

def self.abs n
  (n[0] - n[1]).abs
end

.diff(n) ⇒ Object 



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# File 'lib/mm/deltas.rb', line 7

def self.diff n
  n[0] - n[1]
end

.direction(n) ⇒ Object

Have to scale by 0.5 in order to normalize to a max distance of 1.0



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# File 'lib/mm/deltas.rb', line 16

def self.direction n
  (n[0] <=> n[1]) * 0.5
end

.log_ratio(n) ⇒ Object

Accepts a tuple of anything that Math.log2 can handle



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# File 'lib/mm/deltas.rb', line 26

def self.log_ratio n
  Math.log2((n[0] / n[1]).to_f).abs
end

.mean(n) ⇒ Object 



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# File 'lib/mm/deltas.rb', line 11

def self.mean n
  n.inject(0.0, :+) / n.size
end

.ratio(n) ⇒ Object 



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# File 'lib/mm/deltas.rb', line 30

def self.ratio n
  n[0] / n[1]
end

.tenney(n) ⇒ Object

Accepts a tuple where the quotient responds to #numerator and #denominator



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# File 'lib/mm/deltas.rb', line 21

def self.tenney n
  ->(r) { Math.log2(r.numerator * r.denominator) }.call(n[0] / n[1])
end