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 = BHTree(redirection="none")
instance.particles.add_particles(particles)
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 test13(self):
convert_nbody = nbody_system.nbody_to_si(1.0 | units.kg, 1.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
particles = datamodel.Particles(2)
self.assertEquals(len(instance.particles), 0)
particles.mass = [30.0, 30.0] | units.kg
particles.radius = [1.0, 1.0] | units.m
particles.position = [[-10.0, 0.0, 0.0], [10.0, 0.0, 0.0]] | units.m
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.m / units.s
instance.particles.add_particles(particles)
instance.commit_particles()
copyof = instance.particles.copy()
com = instance.center_of_mass_position
self.assertAlmostEqual(com[0], quantities.new_quantity(0.0, units.m),
constants.precision)
instance.stop()
def test22(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 = 0.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 1.0 | nbody_system.mass
instance = BHTree()
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertEquals(instance.particles[0].radius, 0.0 | nbody_system.length)
p = datamodel.Particle(
x = 1.0 | nbody_system.length,
y = 2.0 | nbody_system.length,
z = 3.0 | nbody_system.length,
vx = 1.0 | nbody_system.speed,
vy = 2.0 | nbody_system.speed,
vz = 3.0 | nbody_system.speed,
mass = 1.0 | nbody_system.mass,
radius = 4.0 | nbody_system.length,
)
instance.particles.add_particle(p)
self.assertEquals(instance.particles[0].radius, 0.0 | nbody_system.length)
self.assertEquals(instance.particles[1].radius, 0.0 | nbody_system.length)
self.assertEquals(instance.particles[2].radius, 4.0 | nbody_system.length)
instance.stop()
def test22(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 = 0.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 1.0 | nbody_system.mass
instance = BHTree()
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertEquals(instance.particles[0].radius,
0.0 | nbody_system.length)
p = datamodel.Particle(
x=1.0 | nbody_system.length,
y=2.0 | nbody_system.length,
z=3.0 | nbody_system.length,
vx=1.0 | nbody_system.speed,
vy=2.0 | nbody_system.speed,
vz=3.0 | nbody_system.speed,
mass=1.0 | nbody_system.mass,
radius=4.0 | nbody_system.length,
)
instance.particles.add_particle(p)
self.assertEquals(instance.particles[0].radius,
0.0 | nbody_system.length)
self.assertEquals(instance.particles[1].radius,
0.0 | nbody_system.length)
self.assertEquals(instance.particles[2].radius,
4.0 | nbody_system.length)
instance.stop()
def test16(self):
numpy.random.seed(0)
number_of_stars = 2
stars = plummer.new_plummer_model(number_of_stars)
stars.radius = 0.00001 | nbody_system.length
stars.scale_to_standard()
instance = BHTree()
instance.initialize_code()
instance.parameters.epsilon_squared = (1.0 / 20.0 /
(number_of_stars**0.33333)
| nbody_system.length)**2
instance.parameters.timestep = 0.004 | nbody_system.time
instance.parameters.timestep = 0.00001 | nbody_system.time
instance.commit_parameters()
print instance.parameters.timestep
instance.particles.add_particles(stars)
instance.commit_particles()
energy_total_t0 = instance.potential_energy + instance.kinetic_energy
request = instance.evolve_model. async (1.0 | nbody_system.time)
request.result()
energy_total_t1 = instance.potential_energy + instance.kinetic_energy
self.assertAlmostRelativeEqual(energy_total_t0, energy_total_t1, 3)
instance.stop()
numpy.random.seed()
def test7(self):
convert_nbody = nbody_system.nbody_to_si(5.0 | units.kg,
10.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
particles = datamodel.Particles(2)
self.assertEquals(len(instance.particles), 0)
particles.mass = [15.0, 30.0] | units.kg
particles.radius = [10.0, 20.0] | units.m
particles.position = [[10.0, 20.0, 30.0], [20.0, 40.0, 60.0]] | units.m
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.m / units.s
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertEquals(instance.get_mass(1), 15.0 | units.kg)
self.assertAlmostRelativeEquals(
instance.get_position(1)[2], 30.0 | units.m)
self.assertEquals(len(instance.particles), 2)
self.assertAlmostRelativeEquals(instance.particles.mass[1],
30.0 | units.kg)
self.assertAlmostRelativeEquals(instance.particles.position[1][2],
60.0 | units.m)
instance.cleanup_code()
instance.stop()
def new_star_code_bhtree(self):
result = BHTree()
result.parameters.epsilon_squared = self.star_epsilon**2
result.parameters.timestep = 0.125 * self.interaction_timestep
result.particles.add_particles(self.new_particles_cluster())
result.commit_particles()
return result
def test6(self):
convert_nbody = nbody_system.nbody_to_si(5.0 | units.kg,
10.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
indices = instance.new_particle(
[15.0, 30.0] | units.kg,
[10.0, 20.0] | units.m,
[20.0, 40.0] | units.m,
[30.0, 50.0] | units.m,
#1.0 | units.m/units.s, 1.0 | units.m/units.s, 3.0 | units.m/units.s
[0.0, 0.01] | units.m / units.s,
[0.0, 0.01] | units.m / units.s,
[0.0, 0.01] | units.m / units.s,
[10.0, 20.0] | units.m)
instance.commit_particles()
self.assertEquals(instance.get_mass(indices[0]), 15.0 | units.kg)
self.assertEquals(instance.get_mass(indices)[0], 15.0 | units.kg)
self.assertRaises(
AmuseException,
instance.get_mass, [4, 5],
expected_message=
"Error when calling 'get_mass' of a 'BHTree', errorcode is -1")
instance.cleanup_code()
instance.stop()
def test7(self):
convert_nbody = nbody_system.nbody_to_si(5.0 | units.kg, 10.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
particles = datamodel.Particles(2)
self.assertEquals(len(instance.particles), 0)
particles.mass = [15.0, 30.0] | units.kg
particles.radius = [10.0, 20.0] | units.m
particles.position = [[10.0, 20.0, 30.0], [20.0, 40.0, 60.0]] | units.m
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.m / units.s
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertEquals(instance.get_mass(1), 15.0| units.kg)
self.assertAlmostRelativeEquals(instance.get_position(1)[2], 30.0| units.m)
self.assertEquals(len(instance.particles), 2)
self.assertAlmostRelativeEquals(instance.particles.mass[1], 30.0 | units.kg)
self.assertAlmostRelativeEquals(instance.particles.position[1][2], 60.0 | units.m)
instance.cleanup_code()
instance.stop()
def new_gas_code_bhtree(self):
result = BHTree(self.converter)
result.parameters.epsilon_squared = self.gas_epsilon ** 2
result.parameters.timestep = 0.125 * self.interaction_timestep
result.particles.add_particles(self.new_particles_cluster_as_gas())
result.commit_particles()
return result
def test2(self):
#not completed
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun,
149.5e6 | units.km)
instance = BHTree(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,
"bhtree-earth-sun.svg")
figure.savefig(output_file)
instance.cleanup_code()
instance.stop()
def test2(self):
#not completed
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 149.5e6 | units.km)
instance = BHTree(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, "bhtree-earth-sun.svg")
figure.savefig(output_file)
instance.cleanup_code()
instance.stop()
def test10(self):
instance = BHTree()
instance.initialize_code()
instance.parameters.epsilon_squared = 0.00001 | nbody_system.length**2
instance.commit_parameters()
particles = datamodel.Particles(6)
particles.mass = 1.0 | nbody_system.mass
particles.radius = 0.00001 | nbody_system.length
particles.position = [[-1.0, 0.0, 0.0], [1.0, 0.0, 0.0],
[0.0, -1.0, 0.0], [0.0, 1.0, 0.0],
[0.0, 0.0, -1.0], [0.0, 0.0, 1.0]
] | nbody_system.length
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0], [
0.0, 0.0, 0.0
], [0.0, 0.0, 0.0], [0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | nbody_system.speed
instance.particles.add_particles(particles)
instance.commit_particles()
zero = 0.0 | nbody_system.length
fx, fy, fz = instance.get_gravity_at_point(zero, zero, zero, zero)
self.assertAlmostEqual(fx, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fy, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fz, 0.0 | nbody_system.acceleration, 3)
for position in (0.25, 0.5, 0.75):
p0 = position | nbody_system.length
p1 = -position | nbody_system.length
for i in range(3):
args0 = [zero] * 4
args1 = [zero] * 4
args0[1 + i] = p0
args1[1 + i] = p1
f0 = instance.get_gravity_at_point(*args0)
f1 = instance.get_gravity_at_point(*args1)
for j in range(3):
if j != i:
self.assertAlmostEqual(f0[j],
0.0 | nbody_system.acceleration,
3)
self.assertAlmostEqual(f1[j],
0.0 | nbody_system.acceleration,
3)
else:
self.assertAlmostEqual(f0[j], -1.0 * f1[j], 5)
instance.stop()
def test5(self):
instance = BHTree()
instance.commit_parameters()
index = instance.new_particle(
15.0 | nbody_system.mass, 10.0 | nbody_system.length,
20.0 | nbody_system.length, 30.0 | nbody_system.length,
1.0 | nbody_system.speed, 1.0 | nbody_system.speed,
3.0 | nbody_system.speed, 10.0 | nbody_system.length)
instance.commit_particles()
self.assertEquals(instance.get_mass(index), 15.0 | nbody_system.mass)
self.assertEquals(instance.get_radius(index),
10.0 | nbody_system.length)
instance.cleanup_code()
instance.stop()
def test5(self):
instance = BHTree()
instance.commit_parameters()
index = instance.new_particle(
15.0 | nbody_system.mass,
10.0 | nbody_system.length, 20.0 | nbody_system.length, 30.0 | nbody_system.length,
1.0 | nbody_system.speed, 1.0 | nbody_system.speed, 3.0 | nbody_system.speed,
10.0 | nbody_system.length
)
instance.commit_particles()
self.assertEquals(instance.get_mass(index), 15.0| nbody_system.mass)
self.assertEquals(instance.get_radius(index), 10.0| nbody_system.length)
instance.cleanup_code()
instance.stop()
def test12(self):
convert_nbody = nbody_system.nbody_to_si(5.0 | units.kg,
10.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
particles = datamodel.Particles(2)
self.assertEquals(len(instance.particles), 0)
particles.mass = [15.0, 30.0] | units.kg
particles.radius = [10.0, 20.0] | units.m
particles.position = [[10.0, 20.0, 30.0], [20.0, 40.0, 60.0]] | units.m
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]
] | units.m / units.s
instance.particles.add_particles(particles)
instance.commit_particles()
copyof = instance.particles.copy()
instance.set_state(1, 16 | units.kg, 20.0 | units.m, 40.0 | units.m,
60.0 | units.m, 1.0 | units.ms, 1.0 | units.ms,
1.0 | units.ms)
curr_state = instance.get_state(1)
for expected, actual in zip(
(16 | units.kg, 20.0 | units.m, 40.0 | units.m, 60.0 | units.m,
1.0 | units.ms, 1.0 | units.ms, 1.0 | units.ms, 0 | units.m),
curr_state):
self.assertAlmostRelativeEquals(actual, expected)
instance.set_state(1, 16 | units.kg, 20.0 | units.m, 40.0 | units.m,
60.0 | units.m, 1.0 | units.ms, 1.0 | units.ms,
1.0 | units.ms, 20.0 | units.m)
curr_state = instance.get_state(1)
for expected, actual in zip(
(16 | units.kg, 20.0 | units.m, 40.0 | units.m, 60.0 | units.m,
1.0 | units.ms, 1.0 | units.ms, 1.0 | units.ms, 20 | units.m),
curr_state):
self.assertAlmostRelativeEquals(actual, expected)
instance.stop()
def test4(self):
convert_nbody = nbody_system.nbody_to_si(5.0 | units.kg, 10.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
index = instance.new_particle(
15.0 | units.kg,
10.0 | units.m, 20.0 | units.m, 30.0 | units.m,
#1.0 | units.m/units.s, 1.0 | units.m/units.s, 3.0 | units.m/units.s
0.0 | units.m/units.s, 0.0 | units.m/units.s, 0.0 | units.m/units.s,
10.0 | units.m
)
instance.commit_particles()
self.assertEquals(instance.get_mass(index), 15.0| units.kg)
self.assertEquals(instance.get_radius(index), 10.0| units.m)
instance.cleanup_code()
instance.stop()
def test15(self):
print "Test15: Testing effect of BHTree 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 = BHTree(convert_nbody)
instance.initialize_code()
instance.parameters.epsilon_squared = 10.0**log_eps2 | units.AU**2
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 test10(self):
instance = BHTree()
instance.initialize_code()
instance.parameters.epsilon_squared = 0.00001 | nbody_system.length**2
instance.commit_parameters()
particles = datamodel.Particles(6)
particles.mass = 1.0 | nbody_system.mass
particles.radius = 0.00001 | nbody_system.length
particles.position = [[-1.0,0.0,0.0],[1.0,0.0,0.0],[0.0,-1.0,0.0],[0.0,1.0,0.0],[0.0,0.0,-1.0],[0.0,0.0,1.0]] | nbody_system.length
particles.velocity = [[0.0,0.0,0.0],[0.0,0.0,0.0],[0.0,0.0,0.0],[0.0,0.0,0.0],[0.0,0.0,0.0],[0.0,0.0,0.0]] | nbody_system.speed
instance.particles.add_particles(particles)
instance.commit_particles()
zero = 0.0 | nbody_system.length
fx, fy, fz = instance.get_gravity_at_point(zero, zero, zero, zero)
self.assertAlmostEqual(fx, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fy, 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(fz, 0.0 | nbody_system.acceleration, 3)
for position in (0.25, 0.5, 0.75):
p0 = position | nbody_system.length
p1 = -position | nbody_system.length
for i in range(3):
args0 = [zero] * 4
args1 = [zero] * 4
args0[1 + i] = p0
args1[1 + i] = p1
f0 = instance.get_gravity_at_point(*args0)
f1 = instance.get_gravity_at_point(*args1)
for j in range(3):
if j != i:
self.assertAlmostEqual(f0[j], 0.0 | nbody_system.acceleration, 3)
self.assertAlmostEqual(f1[j], 0.0 | nbody_system.acceleration, 3)
else:
self.assertAlmostEqual(f0[j], -1.0 * f1[j], 5)
instance.stop()
def test21(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.radius = 0.005 | nbody_system.length
particles.vx = 0.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 1.0 | nbody_system.mass
very_short_time_to_evolve = 1 | units.s
very_long_time_to_evolve = 1e9 | nbody_system.time
instance = BHTree()
instance.initialize_code()
instance.parameters.epsilon_squared = (1e-5 | nbody_system.length)**2
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertAlmostRelativeEquals(instance.potential_energy, -0.1 | nbody_system.energy, 5)
instance.stop()
def test4(self):
convert_nbody = nbody_system.nbody_to_si(5.0 | units.kg,
10.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
index = instance.new_particle(
15.0 | units.kg,
10.0 | units.m,
20.0 | units.m,
30.0 | units.m,
#1.0 | units.m/units.s, 1.0 | units.m/units.s, 3.0 | units.m/units.s
0.0 | units.m / units.s,
0.0 | units.m / units.s,
0.0 | units.m / units.s,
10.0 | units.m)
instance.commit_particles()
self.assertEquals(instance.get_mass(index), 15.0 | units.kg)
self.assertEquals(instance.get_radius(index), 10.0 | units.m)
instance.cleanup_code()
instance.stop()
def test6(self):
convert_nbody = nbody_system.nbody_to_si(5.0 | units.kg, 10.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
indices = instance.new_particle(
[15.0, 30.0] | units.kg,
[10.0, 20.0] | units.m, [20.0, 40.0] | units.m, [30.0, 50.0] | units.m,
#1.0 | units.m/units.s, 1.0 | units.m/units.s, 3.0 | units.m/units.s
[0.0, 0.01] | units.m/units.s, [0.0, 0.01] | units.m/units.s, [0.0, 0.01] | units.m/units.s,
[10.0, 20.0] | units.m
)
instance.commit_particles()
self.assertEquals(instance.get_mass(indices[0]), 15.0| units.kg)
self.assertEquals(instance.get_mass(indices)[0], 15.0| units.kg)
self.assertRaises(AmuseException, instance.get_mass, [4,5],
expected_message = "Error when calling 'get_mass' of a 'BHTree', errorcode is -1")
instance.cleanup_code()
instance.stop()
def test21(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.radius = 0.005 | nbody_system.length
particles.vx = 0.0 | nbody_system.speed
particles.vy = 0.0 | nbody_system.speed
particles.vz = 0.0 | nbody_system.speed
particles.mass = 1.0 | nbody_system.mass
very_short_time_to_evolve = 1 | units.s
very_long_time_to_evolve = 1e9 | nbody_system.time
instance = BHTree()
instance.initialize_code()
instance.parameters.epsilon_squared = (1e-5 | nbody_system.length)**2
instance.particles.add_particles(particles)
instance.commit_particles()
self.assertAlmostRelativeEquals(instance.potential_energy,
-0.1 | nbody_system.energy, 5)
instance.stop()
def test12(self):
convert_nbody = nbody_system.nbody_to_si(5.0 | units.kg, 10.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
particles = datamodel.Particles(2)
self.assertEquals(len(instance.particles), 0)
particles.mass = [15.0, 30.0] | units.kg
particles.radius = [10.0, 20.0] | units.m
particles.position = [[10.0, 20.0, 30.0], [20.0, 40.0, 60.0]] | units.m
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.m / units.s
instance.particles.add_particles(particles)
instance.commit_particles()
copyof = instance.particles.copy()
instance.set_state(1, 16|units.kg, 20.0|units.m, 40.0|units.m, 60.0|units.m,
1.0|units.ms, 1.0|units.ms, 1.0|units.ms)
curr_state = instance.get_state(1)
for expected, actual in zip((16|units.kg, 20.0|units.m, 40.0|units.m, 60.0|units.m,
1.0|units.ms, 1.0|units.ms, 1.0|units.ms, 0 | units.m), curr_state):
self.assertAlmostRelativeEquals(actual,expected)
instance.set_state(1, 16|units.kg, 20.0|units.m, 40.0|units.m, 60.0|units.m,
1.0|units.ms, 1.0|units.ms, 1.0|units.ms , 20.0|units.m)
curr_state = instance.get_state(1)
for expected, actual in zip((16|units.kg, 20.0|units.m, 40.0|units.m, 60.0|units.m,
1.0|units.ms, 1.0|units.ms, 1.0|units.ms, 20 | units.m), curr_state):
self.assertAlmostRelativeEquals(actual,expected)
instance.stop()
def test13(self):
convert_nbody = nbody_system.nbody_to_si(1.0 | units.kg, 1.0 | units.m)
instance = BHTree(convert_nbody)
instance.commit_parameters()
particles = datamodel.Particles(2)
self.assertEquals(len(instance.particles), 0)
particles.mass = [30.0, 30.0] | units.kg
particles.radius = [1.0, 1.0] | units.m
particles.position = [[-10.0, 0.0, 0.0], [10.0, 0.0, 0.0]] | units.m
particles.velocity = [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]] | units.m / units.s
instance.particles.add_particles(particles)
instance.commit_particles()
copyof = instance.particles.copy()
com = instance.center_of_mass_position
self.assertAlmostEqual(com[0], quantities.new_quantity(0.0, units.m), constants.precision)
instance.stop()
def test3(self):
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun,
149.5e6 | units.km)
instance = BHTree(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 test3(self):
convert_nbody = nbody_system.nbody_to_si(1.0 | units.MSun, 149.5e6 | units.km)
instance = BHTree(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 test16(self):
numpy.random.seed(0)
number_of_stars = 2
stars = plummer.new_plummer_model(number_of_stars)
stars.radius = 0.00001 | nbody_system.length
stars.scale_to_standard()
instance = BHTree()
instance.initialize_code()
instance.parameters.epsilon_squared = (1.0 / 20.0 / (number_of_stars**0.33333) | nbody_system.length)**2
instance.parameters.timestep = 0.004 | nbody_system.time
instance.parameters.timestep = 0.00001 | nbody_system.time
instance.commit_parameters()
print instance.parameters.timestep
instance.particles.add_particles(stars)
instance.commit_particles()
energy_total_t0 = instance.potential_energy + instance.kinetic_energy
request = instance.evolve_model.async(1.0 | nbody_system.time)
request.result()
energy_total_t1 = instance.potential_energy + instance.kinetic_energy
self.assertAlmostRelativeEqual(energy_total_t0, energy_total_t1, 3)
instance.stop()
numpy.random.seed()
def test15(self):
print "Test15: Testing effect of BHTree 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 = BHTree(convert_nbody)
instance.initialize_code()
instance.parameters.epsilon_squared = 10.0**log_eps2 | units.AU ** 2
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 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 = BHTree(redirection="none")
instance.particles.add_particles(particles)
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 simulate_small_cluster(number_of_stars, end_time=40 | units.Myr,
name_of_the_figure="test-2.svg"):
# numpy.random.seed(1)
salpeter_masses = new_salpeter_mass_distribution(number_of_stars)
total_mass = salpeter_masses.sum()
convert_nbody = nbody_system.nbody_to_si(total_mass, 1.0 | units.parsec)
particles = new_plummer_model(number_of_stars, convert_nbody)
gravity = BHTree(convert_nbody)
gravity.initialize_code()
# gravity.parameters.set_defaults()
# print gravity.parameters.timestep.as_quantity_in(units.Myr)
gravity.parameters.timestep = 0.0001 | units.Myr # tiny!
gravity.parameters.epsilon_squared \
= (float(number_of_stars)**(-0.333333) | units.parsec) ** 2
stellar_evolution = SSE()
stellar_evolution.initialize_module_with_default_parameters()
print "setting masses of the stars"
particles.radius = 0.0 | units.RSun
particles.mass = salpeter_masses
print "initializing the particles"
stellar_evolution.particles.add_particles(particles)
from_stellar_evolution_to_model \
= stellar_evolution.particles.new_channel_to(particles)
from_stellar_evolution_to_model.copy_attributes(["mass"])
print "centering the particles"
particles.move_to_center()
print "scaling particles to viridial equilibrium"
particles.scale_to_standard(convert_nbody)
gravity.particles.add_particles(particles)
from_model_to_gravity = particles.new_channel_to(gravity.particles)
from_gravity_to_model = gravity.particles.new_channel_to(particles)
gravity.commit_particles()
time = 0.0 | units.Myr
particles.savepoint(time)
total_energy_at_t0 = gravity.kinetic_energy + gravity.potential_energy
print "evolving the model until t = " + str(end_time)
while time < end_time:
time += 0.25 | units.Myr
print "Gravity evolve step starting"
gravity_evolve = gravity.evolve_model.async(time)
print "Stellar evolution step starting"
stellar_evolution_evolve = stellar_evolution.evolve_model(time)
print "Stellar evolution step done."
gravity_evolve.result()
print "Gravity evolve step done."
from_gravity_to_model.copy()
from_stellar_evolution_to_model.copy_attributes(["mass", "radius"])
particles.savepoint(time)
from_model_to_gravity.copy_attributes(["mass"])
total_energy_at_this_time \
= gravity.kinetic_energy + gravity.potential_energy
print_log(time, gravity, particles,
total_energy_at_t0, total_energy_at_this_time)
test_results_path = get_path_to_results()
output_file = os.path.join(test_results_path, "small.hdf5")
if os.path.exists(output_file):
os.remove(output_file)
storage = store.StoreHDF(output_file)
storage.store(particles)
gravity.stop()
stellar_evolution.stop()
plot_particles(particles, name_of_the_figure)
def assignment_2d():
current_cluster_mass = 400 | units.MSun
initial_mass_fraction = 0.84
desired_initial_mass = current_cluster_mass / initial_mass_fraction
masses = new_salpeter_mass_distribution(100000)
mean_salpeter_mass = masses.mean()
print "mean salpeter mass", mean_salpeter_mass
N = int(desired_initial_mass / mean_salpeter_mass)
print "N", N
Rvir = 10 | units.lightyear
z = 0.17
masses = new_salpeter_mass_distribution(N)
converter = nbody_system.nbody_to_si(masses.sum(), Rvir)
G_SI = converter.to_si(nbody_system.G)
bodies = new_plummer_sphere(N, convert_nbody=converter)
bodies.mass = masses
bodies.metalicity = z
# start the gravity solver
gravity = BHTree(converter)
gravity.initialize_code()
gravity.parameters.timestep = 0.1 | units.Myr
# start the stellar evolution solver
stellar = SSE()
stars = stellar.particles.add_particles(bodies)
from_stellar_evolution_to_model \
= stellar.particles.new_channel_to(bodies)
from_stellar_evolution_to_model.copy_attributes(["mass"])
bodies.scale_to_standard(converter)
gravity.particles.add_particles(bodies)
from_model_to_gravity = bodies.new_channel_to(gravity.particles)
from_gravity_to_model = gravity.particles.new_channel_to(bodies)
gravity.commit_particles()
end_time = 1000 | units.Myr
current_time = 0 | units.Myr
cluster = "Hyades"
bound_stars_counts = []
main_sequence_stars_counts = []
giant_stars_counts = []
remnant_stars_counts = []
max_radii = [] | units.parsec
virial_radii = [] | units.parsec
times = [] | units.Myr
while current_time < end_time:
name_of_the_figure = "isochrone_with_grav_"+str(int(current_time.value_in(units.Myr)))+".png"
gravity.evolve_model(current_time)
stellar.evolve_model(current_time)
from_gravity_to_model.copy()
from_stellar_evolution_to_model.copy_attributes(["mass", "radius"])
from_model_to_gravity.copy_attributes(["mass"])
remnant_count = 0
main_sequence_count = 0
giant_count = 0
for star in stars:
if stellar_remnant_state(star):
remnant_count += 1
if stellar_giant_state(star):
giant_count += 1
if stellar_main_sequence_state(star):
main_sequence_count += 1
max_radius = bodies.total_radius()
virial_radius = bodies.virial_radius()
bound_star_count = len(bodies.bound_subset(unit_converter=converter, G=G_SI))
print "bound stars:", bound_star_count
print "main sequence stars:", main_sequence_count
print "giant stars:", giant_count
print "remnant stars:", remnant_count
print "cluster radius(max from centre):", max_radius
print "virial radius:", virial_radius
print current_time
times.append(current_time)
remnant_stars_counts.append(remnant_count)
giant_stars_counts.append(giant_count)
main_sequence_stars_counts.append(main_sequence_count)
max_radii.append(max_radius)
virial_radii.append(virial_radius)
bound_stars_counts.append(bound_star_count)
temperatures = stars.temperature
luminosities = stars.luminosity
plot_HR_diagram(temperatures, luminosities,
cluster+"/",
name_of_the_figure, current_time)
current_time += 10 | units.Myr
data = {}
data["bound_stars_at_time"] = bound_stars_counts
data["remnant_stars_at_time"] = remnant_stars_counts
data["giant_stars_at_time"] = giant_stars_counts
data["main_sequence_stars_at_time"] = main_sequence_stars_counts
data["max_radius_at_time"] = max_radii
data["virial_radii"] = virial_radii
data["times"] = times
pickle.dump(data, open(cluster+"/assignment2d.dat", "wb"))
