Class: DBSCAN::Clusterer

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(points, options = {}) ⇒ Clusterer

Returns a new instance of Clusterer.



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# File 'lib/dbscan.rb', line 18

def initialize( points, options = {} )
	options[:distance] = :euclidean_distance if !options[:distance]
	options[:labels] = [] if !options[:labels]

	c = 0
	@points, @options, @clusters = points.map { |e| po = Point.new(e, options[:labels][c] ); c +=1; po }, options, {-1 => []}

	clusterize!
end

Instance Attribute Details

#clusters ⇒ Object

Returns the value of attribute clusters.



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

def clusters
  @clusters
end

#options ⇒ Object

Returns the value of attribute options.



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

def options
  @options
end

#points ⇒ Object

Returns the value of attribute points.



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

def points
  @points
end

Instance Method Details

#add_connected(neighbors, current_cluster) ⇒ Object 



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# File 'lib/dbscan.rb', line 75

def add_connected( neighbors, current_cluster )
	cluster_points = []
	neighbors.each do |point|
		if !point.visited?
			point.visit!
			new_points = inmediate_neighbors(point)

			if new_points.size >= options[:min_points]
				new_points.each do |p|
					if !neighbors.include?(p)
						neighbors.push( p )
					end
				end
			end
		end

		if !point.cluster
			cluster_points.push( point )
			point.cluster = current_cluster
		end
	end

	cluster_points
end

#clusterize! ⇒ Object 



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# File 'lib/dbscan.rb', line 28

def clusterize!
	current_cluster = -1
	@points.each do |point|
		if !point.visited?
			point.visit!
			neighbors = inmediate_neighbors( point )
			if neighbors.size >= options[:min_points]
				current_cluster += 1
				point.cluster = current_cluster
				cluster = [point].push( add_connected( neighbors, current_cluster ))
				clusters[current_cluster] = cluster.flatten
			else
				clusters[-1].push( point )
			end
		end
	end

end

#inmediate_neighbors(point) ⇒ Object 



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# File 'lib/dbscan.rb', line 64

def inmediate_neighbors( point )
	neighbors = []
	@points.each do |p|
		if p.items != point.items
			d = eval("point.items.#{options[:distance]}( p.items )")
			neighbors.push( p ) if d < options[:epsilon]
		end
	end
	neighbors
end

#labeled_results ⇒ Object 



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# File 'lib/dbscan.rb', line 53

def labeled_results
		hash = {}
		@clusters.each do |cluster_index, elements|
			hash.store( cluster_index, [] )
			elements.each do |e|
				hash[cluster_index].push( e.label )
			end
		end
	hash
end

#results ⇒ Object 



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# File 'lib/dbscan.rb', line 47

def results
	hash = {}
	@clusters.dup.each { |cluster_index, value| hash[cluster_index] = value.flatten.map(&:items) if !value.flatten.empty? }
	hash
end