construct20.rb

def f2(n)
	return n.odd? ? (n * 3 + 1) / 2 : n / 2

end

def adj(x, m, n, s2, p2, p, x3)
	s2.replace(p[0...x] + (x3 % 2).to_s)
	m = (s2[x, 1] == p[x, 1])
	n = p2.reverse.to_i(2)
	p2[x, 1] = m ? '11' : '01'
	return m, n, x3
end

def terras121(p)
	
	p2 = ['01', '11'][p[0, 1].to_i]
	n = 1
	n3 = 0
	m = p2 == '11'
	x3 = (p2.reverse.to_i(2)) >> 1

	(1...p.length).each \
	{
		|x|

		if (!m)
			ns = n.to_s(2)
			ns[0, 1] = ''
			m1 = x3 - 3**n3
			n1 = f2(m1)
		end

		n3 = p[0...x].split('').select { |z| z == '1' }.size
		
		s2 = ''
		m, n, x3 = adj(x, m, n, s2, p2, p, m ? (f2(x3) + 3**n3) : (n1 + 3**n3))
	}

	n = p2.reverse.to_i(2)

	return n
end

def dense(w, d)
	w2 = w - 1
	
	a = (0...w2).to_a
	s = '0' * w2
	(1..(d * w - 1)).map { a.delete_at(rand(a.size)) }.each { |x| s[x, 1] = '1' }
	return ('1' + s)
	
end

def seq(n)
	n1 = n
	l = [n1]
	while (n != 1)
		n = f2(n)
		l << n
	end
	return l
end


def d(s)
        c = s.split('').select { |x| x == '1' }.size
	d = c.to_f / s.length
        return d
        
end

def count(l)
	z = [0, 0]
	l.each \
	{
		|x|
		x.split('').each { |y| z[y.to_i] += 1 }
	}
	return z[0], z[1]
		
end

def avg(l)
	return 0 if (l.nil?)
	l.inject { |t, x| t + x }.to_f / l.size
end

f = File.open('gnuplot.cmd', 'w')
f.puts('$dat << eof')
f.puts(['d1', 'ba', 'ma', 'da', 'w'].join("\t"))

w = 500
c = 100
(0...20).each \
{
	|j|
	
	w = (j + 1) * 25
	(c + 1).times \
	{
		|i|
		
		d1 = i.to_f / c
		n = terras121(dense(100, d1))

		l = seq(n)
		
		tb = tm = td = 0
		l[0...w].each \
		{
			|x|
			ns = x.to_s(2)
			d = d(x.to_s(2))
			td += d
			b = d > 0.5 ? 1 : 0
			tb += b
			tm += ns[-1, 1].to_i ^ b ^ 1
		}
		f.puts([d1, tb.to_f / w, tm.to_f / w, td / w, w].join("\t"))
	}
	f.puts
}

f.puts('eof')
['ba', 'ma', 'da'].each \
{
	|x|
	f.puts("plot $dat using (column('d1')):(column('#{x}')):(column('w')) with line linecolor palette lw 2 title '#{x}'; pause -1;")
}
f.close