Class: Carmenere::KMeans::Algorithm

Inherits:
Algorithm
  • Object
show all
Defined in:
lib/carmenere/kmeans/algorithm.rb

Instance Attribute Summary collapse

Attributes inherited from Algorithm

#distance_matrix, #nodes

Instance Method Summary collapse

Constructor Details

#initialize(centroids, nodes, &mean) ⇒ Algorithm

Returns a new instance of Algorithm.



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# File 'lib/carmenere/kmeans/algorithm.rb', line 22

def initialize centroids, nodes, &mean
  super centroids.count, nodes
  @mean = mean
  @centroids = centroids
end

Instance Attribute Details

#centroids ⇒ Object (readonly)

Returns the value of attribute centroids.



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# File 'lib/carmenere/kmeans/algorithm.rb', line 20

def centroids
  @centroids
end

Instance Method Details

#run ⇒ Object 



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# File 'lib/carmenere/kmeans/algorithm.rb', line 28

def run
  old_centroids = Set.new
  centroids = Set.new @centroids
  centroid_clusters = {nil => nil}
  until Carmenere::KMeans::centroids_eql? old_centroids, centroids
    old_centroids = centroids
    node_centroids = @nodes.each.with_object({}) do |node, h|
      h[node] = centroids.min_by do |c|
        node.distance(c)
      end
    end
    centroid_clusters = centroids.each.with_object({}) do |centroid, h|
      nodes = node_centroids.lazy.select do |_, c|
        c.attr_eql?(centroid)
      end.map do |n, c|
        n
      end
      h[centroid] = Carmenere::KMeans::Cluster.new nodes
    end
    yield centroid_clusters if block_given?
    centroids = Set.new centroid_clusters.values.map do |cluster|
      @mean.call(cluster)
    end
  end
  centroid_clusters
end