seeds

seeds.py

import random, sys
dirs = ["up", "down"]

class Particle:
	def __init__(self, seed, spin):
		self.seed = seed
		self.spin = spin

	def measure(self, angle):
		# return up or down
		# where angle is P(up)
		random.seed(self.seed)
		rando = random.random()
		zeroOrOne = (rando < angle)
		return dirs[self.spin - zeroOrOne]


def create_particles(seed):
	# return two entangled particles
	a1 = Particle(seed, True)
	a2 = Particle(seed, False)

	return (a1, a2)


def sanity_check(seed):
	# generate particles
	p1, p2 = create_particles(seed)

	# when measured with the same angle, should be opposite
	print p1.measure(.5), p2.measure(.5)

def bell_test():
	# measures at 3 different angles randomly
	# and checks % of times they were opposite
	# using random seeds for each set of particles

	# expected output of this is 5/9 opposite

	# init thangs
	same_attempts = same_opp_outputs = same_same_outputs = dif_opp_outputs = dif_same_outputs = dif_attempts = 0

	for x in range(1, 50000):
		# generate particles
		p1, p2 = create_particles(x)

		# which angles we can choose from
		angles = [0.333, 0.666, 0.999]

		# decide on which two angles
		# this is okay on the current seed because
		# of http://stackoverflow.com/a/2221769
		ang1 = random.choice(angles)
		ang2 = random.choice(angles)

		# measure the particles
		m1 = p1.measure(ang1)
		m2 = p2.measure(ang2)

		# increment counters
		same_attempts += (ang1 == ang2)
		same_opp_outputs += (ang1==ang2)*(m1!=m2)
		same_same_outputs += (ang1==ang2)*(m1==m2)

		dif_attempts += (ang1 != ang2)
		dif_opp_outputs += (ang1!=ang2)*(m1!=m2)
		dif_same_outputs += (ang1!=ang2)*(m1==m2)

	# print output
	print "Bell Test", "\n", "-----------"
	print "Number of same angle measurements:", same_attempts
	print "Number of times opposite:", same_opp_outputs
	print "Number of times same:", same_same_outputs
	print "Percent opposite:", (same_opp_outputs/(same_attempts+0.0))
	print ""
	print "Number of different angle measurements:", dif_attempts
	print "Number of times opposite:", dif_opp_outputs
	print "Number of times same:", dif_same_outputs
	print "Percent opposite:", (dif_opp_outputs/(dif_attempts+0.0)), "\n"

def bell_same_particle_test(seed):
	# measures at 3 different angles randomly
	# and checks % of times they were opposite
	# using the same particles each time

	# expected output of this is  opposite

	# init thangs
	same_attempts = same_opp_outputs = same_same_outputs = dif_opp_outputs = dif_same_outputs = dif_attempts = 0

	# generate single particle set 
	p1, p2 = create_particles(seed)

	for x in range(1, 50000):

		# which angles we can choose from
		angles = [0.333, 0.666, 0.999]

		# this on the other hand might not be ok
		random.seed(x)

		ang1 = random.choice(angles)
		ang2 = random.choice(angles)

		# measure the particles
		m1 = p1.measure(ang1)
		m2 = p2.measure(ang2)

		# increment counters
		same_attempts += (ang1 == ang2)
		same_opp_outputs += (ang1==ang2)*(m1!=m2)
		same_same_outputs += (ang1==ang2)*(m1==m2)

		dif_attempts += (ang1 != ang2)
		dif_opp_outputs += (ang1!=ang2)*(m1!=m2)
		dif_same_outputs += (ang1!=ang2)*(m1==m2)

	# print output
	print "Bell Test w/ same particles", "\n", "-----------"
	print "Number of same angle measurements:", same_attempts
	print "Number of times opposite:", same_opp_outputs
	print "Number of times same:", same_same_outputs
	print "Percent opposite:", (same_opp_outputs/(same_attempts+0.0))
	print ""
	print "Number of different angle measurements:", dif_attempts
	print "Number of times opposite:", dif_opp_outputs
	print "Number of times same:", dif_same_outputs
	print "Percent opposite:", (dif_opp_outputs/(dif_attempts+0.0)), "\n"

bell_test()


#def test_2(seed):
	# measures at 3 different angles randomly
	# and checks % of times they were opposite
	# using the same particles each time


#print sanity_check(sys.argv[1])
bell_same_particle_test(sys.argv[1])


#def test_2(seed):
	# measures at 3 different angles randomly
	# and checks % of times they were opposite


#print sanity_check(sys.argv[1])