Class: Classified::Metrics

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

Class Method Summary collapse

Class Method Details

.summary(classifier, metrics) ⇒ Object 



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# File 'lib/metrics.rb', line 61

def self.summary(classifier, metrics)
  puts "average classification time = #{metrics[:duration]/metrics[:total].to_f} secs"
  puts "total classifications = #{metrics[:total]}"
  puts "correct classifications = #{metrics[:correct]}"
  puts "accuracy = #{metrics[:accuracy]}"
  classifier.classifications.each do |classification|
    puts "#{classification} classification metrics"
    metrics[classification].each_key do |metric|
      puts "\t#{metric} = #{metrics[classification][metric]}"
    end
    puts
  end
end

.test_classifier(classifier, test_corpus) ⇒ Object 



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# File 'lib/metrics.rb', line 16

def self.test_classifier classifier, test_corpus
  alpha = 0.5
  total = correct = 0
  metrics = {}

  puts "Getting metrics"
  start_time = Time.now

  classifier.classifications.each do |c|
    # tc - true class
    # fc - false class
    tc = c
    fc = classifier.classifications.clone
    fc.delete(tc)
    fc = fc.first
    metrics[tc] = { :precision => 0, :recall => 0, :fmeasure => 0 }
    scores = {}
    classifier.classifications.each do |classification|
      scores[classification] = { :true => 0, :false => 0 }
    end
    test_corpus.each do |doc|
      c = classifier.transform(doc[:classification])
      if classifier.classify(doc[:text]) ==  c
        scores[c][:true]+=1
      else
        scores[c][:false]+=1
      end
    end
    correct += scores[tc][:true]
    total += scores[tc][:true] + scores[tc][:false]
    metrics[tc][:precision] = scores[tc][:true].to_f / (scores[tc][:true] + scores[tc][:false])
    metrics[tc][:recall] = scores[tc][:true].to_f / (scores[tc][:true] + scores[fc][:false])
    metrics[tc][:fmeasure] = 1.0/(alpha/metrics[tc][:precision] + (1-alpha)/metrics[tc][:recall])
  end

  metrics[:correct] = correct
  metrics[:total] = total
  metrics[:accuracy] = correct.to_f / total
  metrics[:duration] = Time.now-start_time

  puts "Took #{metrics[:duration]} secs"

  metrics
end

.train_classifier(classifier, corpus) ⇒ Object 



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# File 'lib/metrics.rb', line 4

def self.train_classifier classifier, corpus
  puts "Training"
  start_time = Time.now
  corpus.each do |doc|
    classifier.train doc[:classification], doc[:text]
  end
  # Call a classify action to force an syncing in the classifier to occur
  classifier.classify("It's rubbish")
  #classifier.save(:metadata => './metadata', :model => './model')
  puts "Took #{Time.now-start_time} secs : training #{corpus.length} docs"
end