Module: Ablab::AblabHelper

Defined in:
app/helpers/ablab/ablab_helper.rb

Instance Method Summary collapse

Instance Method Details

#confidence(z_score, na = 'n/a') ⇒ Object 



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# File 'app/helpers/ablab/ablab_helper.rb', line 23

def confidence(z_score, na = 'n/a')
  return na if z_score.nil? || z_score.nan?
  z_score = z_score.abs
  if z_score >= 2.58
    '99%'
  elsif z_score >= 1.96
    '95%'
  elsif z_score >= 1.65
    '90%'
  else
    'insufficient'
  end
end

#cr_gain(results_a, results_b, na = 'n/a') ⇒ Object 



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# File 'app/helpers/ablab/ablab_helper.rb', line 37

def cr_gain(results_a, results_b, na = 'n/a')
  return na if results_a[:sessions] == 0 || results_b[:sessions] == 0
  cr_a = results_a[:conversions].to_f / results_a[:sessions]
  cr_b = results_b[:conversions].to_f / results_b[:sessions]
  gain = cr_a - cr_b
  "#{gain >= 0 ? '+' : ''}#{number_to_percentage(gain * 100.0)}"
end

#format_decimal(decimal, na = 'n/a') ⇒ Object 



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# File 'app/helpers/ablab/ablab_helper.rb', line 13

def format_decimal(decimal, na = 'n/a')
  return na if decimal.nil? || decimal.nan?
  number_with_precision(decimal, precision: 3)
end

#format_number(number, na = 'n/a') ⇒ Object 



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# File 'app/helpers/ablab/ablab_helper.rb', line 8

def format_number(number, na = 'n/a')
  return na if number.nil? || number.try(:nan?)
  number_with_delimiter(number)
end

#format_percentage(numerator, denominator, na = 'n/a') ⇒ Object 



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# File 'app/helpers/ablab/ablab_helper.rb', line 3

def format_percentage(numerator, denominator, na = 'n/a')
  return na if denominator == 0
  number_to_percentage((numerator.to_f / denominator) * 100.0)
end

#gains(experiment, group_name) ⇒ Object 



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# File 'app/helpers/ablab/ablab_helper.rb', line 64

def gains(experiment, group_name)
  result = experiment.results[group_name]
  return nil if result[:sessions] == 0
  cr = result[:conversions].to_f / result[:sessions]
  experiment.results.reduce({}) do |hash, (g, r)|
    if r[:sessions] > 0 && g != group_name
      hash[g] = cr - (r[:conversions].to_f / r[:sessions])
    end
    hash
  end
end

#significant?(results) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/helpers/ablab/ablab_helper.rb', line 18

def significant?(results)
  return false if results[:sessions] < 30 || results[:conversions] < 5
  results[:z_score] && results[:z_score] >= 1.65
end

#winner(experiment) ⇒ Object 



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# File 'app/helpers/ablab/ablab_helper.rb', line 49

def winner(experiment)
  @winners ||= {}
  return @winners[experiment.name] if @winners.has_key?(experiment.name)
  winner_name, winner_results = @results[experiment.name].max_by do |(_, r)|
    if r[:sessions] > 0
      r[:conversions].to_f / r[:sessions]
    else
      -1
    end
  end
  @winners[experiment.name] = nil
  @winners[experiment.name] = winner_name if significant?(winner_results)
  @winners[experiment.name]
end

#winner?(experiment, group_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/helpers/ablab/ablab_helper.rb', line 45

def winner?(experiment, group_name)
  winner(experiment) == group_name
end