rwalk2.rb

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 rwalk(u1, d1, z, w)

	x = (z + w * d1) / (u1 + d1)
	y = w - x

	xw = x / w
	$stderr.puts({'z' => z, 'w' => w, 'x' => x, 'y' => y, 'xw' => xw, 'u1' => u1, 'd1' => d1}.inspect)

	d = dense(w, xw)

	return d
end

def walk(s, u1, d1, j)
	c = 0
	s.split('').each_with_index \
	{
		|x, i|
		c += (x == '1') ? u1 : -d1
		puts([i, c, j].join("\t"))
	}
	puts
end

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 fmt1(l, f)

	w = l.max_by { |x| x.length }.length
	
	f.puts("set colors classic; set ytics nomirror; set y2tics; set key top left opaque;\\")
	f.puts("plot \\")
	f.puts("[0:#{w}][0:#{l.size - 1}] '-' matrix using 1:2:3 with image title ''")
	l.each_with_index \
	{
		|z, i|
		
		c = w - z.length
		z[z.length...w] = '0' * c
		
		f.puts(z.split('').join(' '))
	}
	f.puts("eof")
	f.puts("eof")
	
	
end

def grid(l)
	
	f = File.open(fn = "gnuplot1.cmd", 'w')
	f.puts("set palette negative grayscale; unset colorbox;")
	
	fmt1(l.map { |x| x.reverse }, f)
	f.close

end


u = 3.0 / 2
d = 1.0 / 2


u1 = Math.log(u) / Math.log(2)
d1 = -Math.log(d) / Math.log(2)



z = 50
w = 500


wa = (z / u1).to_i
wb = (z / -(u1 - d1) * 2).to_i

f = File.open('out1.txt', 'w')
l2 = []
(wa..(w - wb)).each_with_index \
{
	|w1, j|
	

	s1 = rwalk(u1, d1, z, w1)
	s2 = dense(w - w1, 0.5)
	walk(s1 + s2, u1, d1, j)
	l2 << (s = terras121(s1 + s2).to_s(2))
	f.puts(s)
}
f.close
grid(l2)