def test23(self):
particles = datamodel.Particles(2)
particles.x = [0.0,10.0] | nbody_system.length
particles.y = 0.0 | nbody_system.length
particles.z = 0.0 | nbody_system.length
particles.vx = 1.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 0.1 | nbody_system.mass
instance = FDPS(redirection="none")
instance.particles.add_particles(particles)
instance.parameters.timestep = 0.001 | nbody_system.time
instance.commit_particles()
instance.evolve_model(0.1 | nbody_system.time)
self.assertFalse(instance.particles[0].vy > 0| nbody_system.speed)
self.assertAlmostRelativeEquals(instance.particles[0].x , 0.1 | nbody_system.length, 4)
instance.particles.new_channel_to(particles).copy()
particles.vy = 1| nbody_system.speed
particles.new_channel_to(instance.particles).copy()
instance.evolve_model(0.2 | nbody_system.time)
self.assertTrue(instance.particles[0].vy > 0| nbody_system.speed)
self.assertAlmostRelativeEquals(instance.particles[0].y , 0.1 | nbody_system.length, 4)
instance.stop()
def test2(self):
#not completed
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 149.5e6 | units.km)
instance = FDPS(convert_nbody)
#instance.dt_dia = 1
instance.parameters.epsilon_squared = 0.001 | units.AU**2
#instance.timestep = 0.0001
#instance.use_self_gravity = 0
instance.commit_parameters()
stars = datamodel.Stars(2)
sun = stars[0]
sun.mass = units.MSun(1.0)
sun.position = units.m(numpy.array((0.0,0.0,0.0)))
sun.velocity = units.ms(numpy.array((0.0,0.0,0.0)))
sun.radius = units.RSun(1.0)
earth = stars[1]
earth.mass = units.kg(5.9736e24)
earth.radius = units.km(6371)
earth.position = units.km(numpy.array((149.5e6,0.0,0.0)))
earth.velocity = units.ms(numpy.array((0.0,29800,0.0)))
instance.particles.add_particles(stars)
instance.commit_particles()
self.assertAlmostRelativeEquals(sun.radius, instance.particles[0].radius)
for x in range(1,2000,10):
instance.evolve_model(x | units.day)
instance.particles.copy_values_of_all_attributes_to(stars)
stars.savepoint()
if HAS_MATPLOTLIB:
figure = pyplot.figure()
plot = figure.add_subplot(1,1,1)
x_points = earth.get_timeline_of_attribute("x")
y_points = earth.get_timeline_of_attribute("y")
x_points_in_AU = map(lambda (t,x) : x.value_in(units.AU), x_points)
y_points_in_AU = map(lambda (t,x) : x.value_in(units.AU), y_points)
plot.scatter(x_points_in_AU,y_points_in_AU, color = "b", marker = 'o')
plot.set_xlim(-1.5, 1.5)
plot.set_ylim(-1.5, 1.5)
test_results_path = self.get_path_to_results()
output_file = os.path.join(test_results_path, "fdps-earth-sun.svg")
figure.savefig(output_file)
instance.cleanup_code()
instance.stop()
def test15(self):
print "Test15: Testing effect of FDPS parameter epsilon_squared"
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 1.0 | units.AU)
particles = datamodel.Particles(2)
sun = particles[0]
sun.mass = 1.0 | units.MSun
sun.position = [0.0, 0.0, 0.0] | units.AU
sun.velocity = [0.0, 0.0, 0.0] | units.AU / units.yr
sun.radius = 1.0 | units.RSun
earth = particles[1]
earth.mass = 5.9736e24 | units.kg
earth.radius = 6371.0 | units.km
earth.position = [0.0, 1.0, 0.0] | units.AU
earth.velocity = [2.0*numpy.pi, -0.0001, 0.0] | units.AU / units.yr
initial_direction = math.atan((earth.velocity[0]/earth.velocity[1]))
final_direction = []
for log_eps2 in range(-9,10,2):
instance = FDPS(convert_nbody)
instance.initialize_code()
instance.parameters.epsilon_squared = 10.0**log_eps2 | units.AU ** 2
instance.parameters.timestep = 0.005 | units.yr
instance.particles.add_particles(particles)
instance.commit_particles()
instance.evolve_model(0.25 | units.yr)
final_direction.append(math.atan((instance.particles[1].velocity[0]/
instance.particles[1].velocity[1])))
instance.stop()
# Small values of epsilon_squared should result in normal earth-sun dynamics: rotation of 90 degrees
self.assertAlmostEquals(abs(final_direction[0]), abs(initial_direction+math.pi/2.0), 2)
# Large values of epsilon_squared should result in ~ no interaction
self.assertAlmostEquals(final_direction[-1], initial_direction, 2)
# Outcome is most sensitive to epsilon_squared when epsilon_squared = d(earth, sun)^2
delta = [abs(final_direction[i+1]-final_direction[i]) for i in range(len(final_direction)-1)]
self.assertEquals(delta[len(final_direction)//2 -1], max(delta))
def test3(self):
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 149.5e6 | units.km)
instance = FDPS(convert_nbody)
#instance.dt_dia = 1
instance.parameters.epsilon_squared = 0.001 | units.AU**2
#instance.timestep = 0.0001
#instance.use_self_gravity = 0
instance.commit_parameters()
stars = datamodel.Stars(2)
star1 = stars[0]
star2 = stars[1]
star1.mass = units.MSun(1.0)
star1.position = units.AU(numpy.array((-.10,0.0,0.0)))
star1.velocity = units.AUd(numpy.array((0.0,0.0,0.0)))
star1.radius = units.RSun(1.0)
star2.mass = units.MSun(1.0)
star2.position = units.AU(numpy.array((.10,0.0,0.0)))
star2.velocity = units.AUd(numpy.array((0.0,0.0,0.0)))
star2.radius = units.RSun(100.0)
instance.particles.add_particles(stars)
instance.commit_particles()
for x in range(1,200,1):
instance.evolve_model(x | units.day)
instance.particles.copy_values_of_all_attributes_to(stars)
#instance.get_indices_of_colliding_particles()
#print stars[0].position-stars[1].position
stars.savepoint()
instance.cleanup_code()
instance.stop()
def test1(self):
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 149.5e6 | units.km)
instance = FDPS(convert_nbody)
instance.parameters.epsilon_squared = 0.001 | units.AU**2
stars = datamodel.Stars(2)
sun = stars[0]
sun.mass = units.MSun(1.0)
sun.position = [0.0,0.0,0.0] | units.m
sun.velocity = [0.0,0.0,0.0] | units.ms
sun.radius = units.RSun(1.0)
earth = stars[1]
earth.mass = units.kg(5.9736e24)
earth.radius = units.km(6371)
earth.position = [149.5e6, 0.0, 0.0] | units.km
earth.velocity = [0.0, 29800, 0.0] | units.ms
#instance.particles.add_particles(stars)
instance.particles.add_particles(stars)
postion_at_start = earth.position.value_in(units.AU)[0]
instance.evolve_model(365.0 | units.day)
instance.particles.copy_values_of_all_attributes_to(stars)
postion_after_full_rotation = earth.position.value_in(units.AU)[0]
self.assertAlmostEqual(postion_at_start, postion_after_full_rotation, 3)
instance.evolve_model(365.0 + (365.0 / 2) | units.day)
instance.particles.copy_values_of_all_attributes_to(stars)
postion_after_half_a_rotation = earth.position.value_in(units.AU)[0]
self.assertAlmostEqual(-postion_at_start, postion_after_half_a_rotation, 2)
instance.evolve_model(365.0 + (365.0 / 2) + (365.0 / 4) | units.day)
instance.particles.copy_values_of_all_attributes_to(stars)
postion_after_half_a_rotation = earth.position.value_in(units.AU)[1]
self.assertAlmostEqual(-postion_at_start, postion_after_half_a_rotation, 1)
instance.cleanup_code()
instance.stop()
