Class: Clustering::Simple

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

Instance Method Summary collapse

Constructor Details

#initialize(data) ⇒ Simple

input: “data” should be an array of arrays each array should contain elements that are connected to each other elements are counted as often as they occur in the arrays this class does not make sure to only have unique elements in an array [

[1,2,3],
[2,3],
[3,1]

]



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# File 'lib/clustering/simple.rb', line 14

def initialize(data)
  @original = data
end

Instance Method Details

#clusters(threshold = 2) ⇒ Object 



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# File 'lib/clustering/simple.rb', line 40

def clusters(threshold = 2)
  relations.inject(Hash.new{|h,k| h[k] = Array.new }) do |akk, e|
    key, values = *e
    keys = values.keys.select{|s| s >= threshold}.sort.reverse
    keys.each do |k|
      akk[key].concat values[k]
    end
    akk
  end
end

#connections ⇒ Object

create a hash of hashes which contains the grade of linkage between elements connections[4] #=> 2



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# File 'lib/clustering/simple.rb', line 20

def connections
  @connections ||= @original.inject(Hash.new{|h,k| h[k] = Hash.new(0)}) do |akk, e|
    e.each do |key|
      e.each do |id|
        akk[key][id] += 1 unless key == id
      end
    end
    akk
  end
end

#relations ⇒ Object 



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# File 'lib/clustering/simple.rb', line 31

def relations
  @relations ||= connections.inject(Hash.new{|h,k| h[k] = Hash.new{|h,k| h[k] = Array.new }}) do |akk, e|
    e.last.each do |k,v|
      akk[e.first][v].push k
    end
    akk
  end
end

#strength?(a, b) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/clustering/simple.rb', line 51

def strength?(a, b)
  connections[a][b]
end