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63 lines
1.2 KiB
Ruby
63 lines
1.2 KiB
Ruby
require 'measures'
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class DBscan
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def initialize(distance_measure)
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@measure = distance_measure
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end
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def neighbors(db, info, p, eps)
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neighborhood = []
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db.each do |p_prime|
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if p != p_prime && @measure.distance(p, p_prime) < eps
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neighborhood.push p_prime
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end
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end
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return neighborhood
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end
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def expand_cluster(db, info, p, cluster, c, eps, min_pts)
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cluster.push p
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if info[p] != :visited
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info[p] = :visited
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n = neighbors(db, info, p, eps)
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if n.size >= min_pts
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n.each do |p_prime|
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if not c.map{|c_prime| c_prime.include? p_prime}.include?(true) #not contained in any cluster?
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expand_cluster(db, info, p_prime, cluster, c, eps, min_pts)
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end
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end
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end
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end
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return cluster
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end
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def run(db, eps, min_pts)
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c = []
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info = Hash.new
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db.each do |p|
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if info[p] != :visited
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info[p] = :visited
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n = neighbors(db, info, p, eps)
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if n.size < min_pts
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info[p] = :noise
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else
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cluster = [p] #new cluster
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c.push cluster
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n.each do |p_prime|
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if not c.map{|c_prime| c_prime.include? p_prime}.include?(true) #not contained in any cluster?
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expand_cluster(db, info, p_prime, cluster, c, eps, min_pts)
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end
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end
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end
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end
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end
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return c
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end
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end
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