prefix4.rb

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

end

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

def count2(l, j, w2, f)
	a = {}
	mx = 2 ** w2
	l.each_with_index \
	{
		|n, i|
		s = n.to_s(2)[-w2..-1]
		a[s] = a.fetch(s, 0) + 1
		f.puts([i, a.size.to_f / mx, j].join("\t"))
	}
	f.puts
end

def sample(l, c)

	return l if (l.size <= c)
	r = l.size / c
	l2 = *(0...l.size).select { |x| x % r == 0 }
	l2[c..-1] = []
	return l.values_at(*l2)
	
end

def test(l, w2, f)
		
	(0...l.size).to_a.reverse.each \
	{
		|j|
		
		x = l[j]
		n = x['n']
		
		l1 = seq(n)
		w = x['ns'].length
		
		count2(l1[0..w], j, w2, f)
	}
end

def graph(gp, fn)
		
	l = File.open(fn).readlines.map { |x| Kernel.eval(x) }
	l = sample(l, 100)

	f = File.open(gp, 'a')
	f.puts('$dat << eof')

	(4..10).each \
	{
		|w2|
		test(l, w2, f)
	}

	f.puts('eof')
	f.puts("set title '#{fn}'; plot $dat using 1:2:3 with line linecolor palette")
	f.puts('pause -1')
	f.close
	
end

gp = 'gnuplot.cmd'

fn1 = 'tmp/bitwise9/mixdb_mx.txt'
fn2 = 'tmp/bitwise9/mixdb_a.txt'
File.open(gp, 'w').close
graph(gp, fn1)
graph(gp, fn2)