def jaccard(x,y) #based on http://people.revoledu.com/kardi/tutorial/Similarity/Jaccard.html - asymmetrical
	a1b1 = a0b1 = a1b0 = a0b0 = 0
	x.each_index do |i| 
		if x[i]==0
			if y[i]==0
				a0b0=a0b0+1
			elsif y[i]==1
				a0b1=a0b1+1
			end
		elsif x[i]==1
			if y[i]==0
				a1b0=a1b0+1
			elsif y[i]==1
				a1b1=a1b1+1
			end
		end
	end
	a1b1/(a0b1+a1b0+a1b1).to_f
end

def simplematch(x,y) #based on http://people.revoledu.com/kardi/tutorial/Similarity/SimpleMatching.html
	a1b1 = a0b1 = a1b0 = a0b0 = 0
	x.each_index do |i| #allows looping through both lists at once
		if x[i]==0
			if y[i]==0
				a0b0=a0b0+1
			elsif y[i]==1
				a0b1=a0b1+1
			end
		elsif x[i]==1
			if y[i]==0
				a1b0=a1b0+1
			elsif y[i]==1
				a1b1=a1b1+1
			end
		end
	end
	(a1b1+a0b0).to_f/x.length
end

def simpledistance(x,y)
	1-simplematch(x,y)
end