Class: ABBA::Bayes::BinaryOutcomeTest

Inherits:
Object
  • Object
show all
Defined in:
lib/abba/bayes.rb

Instance Method Summary collapse

Constructor Details

#initialize(variant_a, variant_b) ⇒ BinaryOutcomeTest

Returns a new instance of BinaryOutcomeTest.



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# File 'lib/abba/bayes.rb', line 4

def initialize(variant_a, variant_b)
  @variant_a = variant_a
  @variant_b = variant_b
end

Instance Method Details

#call ⇒ Object 



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# File 'lib/abba/bayes.rb', line 9

def call
  total = 0.0

  (0..(alpha_a-1)).each do |i|
    log_contribution = Math.lbeta(alpha_b+i, beta_a+beta_b) - Math.log(beta_a+i) - Math.lbeta(1+i, beta_a) - Math.lbeta(alpha_b, beta_b)
    total += Math.exp(log_contribution)
  end

  total
end