Module: Math

Defined in:
lib/muflax/math.rb

Overview

Copyright Steffie Dorn <[email protected]>, 2018 License: GNU APGLv3 (or later) <www.gnu.org/copyleft/gpl.html>

Class Method Summary collapse

Class Method Details

.choose(k, n) ⇒ Object 



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# File 'lib/muflax/math.rb', line 35

def choose k, n
  Math.factorial(n) / (Math.factorial(k) * Math.factorial(n - k))
end

.factorial(n) ⇒ Object 



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# File 'lib/muflax/math.rb', line 31

def factorial n
  (2..n).reduce(1){|f, x| f * x}
end

.harmonic(n) ⇒ Object 



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# File 'lib/muflax/math.rb', line 8

def harmonic n
  (1..n).reduce(0.0){|s, i| s + (1.0 / i)}
end

.sufficiency(exceptions) ⇒ Object Also known as: sufficient

TODO meh iterative solution



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# File 'lib/muflax/math.rb', line 24

def sufficiency exceptions
  n = 1
  n += 1 while θ(n) < exceptions
  n
end

.tolerance(total) ⇒ Object Also known as: tolerate, θ 



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# File 'lib/muflax/math.rb', line 16

def tolerance total
  θ = total / Math.log(total)
  θ > total ? total : θ.round
end

.zipf(k, n) ⇒ Object 



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# File 'lib/muflax/math.rb', line 12

def zipf k, n
  1.0 / (k.to_f * harmonic(n))
end