def test1(self):
M=10.
a=2.
x=1.
y=2.
z=3.
r=(x*x+y*y+z*z)**0.5
instance = Agama(type="Dehnen",
mass=M|generic_unit_system.mass, scaleRadius=a|generic_unit_system.length)
result=instance.get_potential_at_point(
0.|generic_unit_system.length,
x |generic_unit_system.length,
y |generic_unit_system.length,
z |generic_unit_system.length)
self.assertAlmostEqual(result.value_in(
generic_unit_system.length**2/generic_unit_system.time**2), -M/(r+a), places=14)
result=instance.get_gravity_at_point(
0.|generic_unit_system.length,
x |generic_unit_system.length,
y |generic_unit_system.length,
z |generic_unit_system.length)
self.assertAlmostEqual(result[0].value_in(
generic_unit_system.length/generic_unit_system.time**2), -M/(r+a)**2 * x/r, places=14)
self.assertAlmostEqual(result[0],result[2]/3, places=14)
scaleM=2.345678|units.MSun
scalea=7.654321|units.parsec
converter=nbody_system.nbody_to_si(scaleM, scalea)
instance = Agama(converter, type="Dehnen", mass=M*scaleM, scaleradius=a*scalea)
result=instance.get_gravity_at_point(
0.|generic_unit_system.length, x*scalea, y*scalea, z*scalea)
scale=M/(r+a)**2 *scaleM/scalea**2*constants.G
self.assertAlmostEqual(result[0], scale * x/r, places=10)
instance.stop()
def test2(self):
seed(1)
particles=new_plummer_model(10000)
instance = Agama(type="Multipole", particles=particles)
result=instance.get_potential_at_point(
0.|generic_unit_system.length,
0.|generic_unit_system.length,
0.|generic_unit_system.length,
0.|generic_unit_system.length)
self.assertLess(abs(result/(-16./3/3.1416|
generic_unit_system.length**2/generic_unit_system.time**2) - 1), 0.04)
scaleM=1234|units.MSun
scaleR=5.6 |units.parsec
converter=nbody_system.nbody_to_si(scaleM,scaleR)
particles=new_plummer_model(20000, convert_nbody=converter)
instance = Agama(converter, type="Multipole", particles=particles)
x=3.|units.parsec
y=4.|units.parsec
z=5.|units.parsec
r=(x*x+y*y+z*z)**0.5
result=instance.get_gravity_at_point(0|units.parsec, x, y, z)
expected=-constants.G*scaleM/(r*r+(3*3.1416/16*scaleR)**2)**1.5*x
self.assertLess(abs(result[0]/expected-1), 0.03)
self.assertLess(abs(result[2]/result[0]-z/x), 0.03)
instance.stop()
def test1(self):
M=10.
a=2.
x=1.
y=2.
z=3.
r=(x*x+y*y+z*z)**0.5
instance = Agama(type="Dehnen", mass=M|generic_unit_system.mass, scaleRadius=a|generic_unit_system.length)
result=instance.get_potential_at_point(
0.|generic_unit_system.length,
x |generic_unit_system.length,
y |generic_unit_system.length,
z |generic_unit_system.length)
self.assertAlmostEqual(result.value_in(generic_unit_system.length**2/generic_unit_system.time**2), -M/(r+a), places=14)
result=instance.get_gravity_at_point(
0.|generic_unit_system.length,
x |generic_unit_system.length,
y |generic_unit_system.length,
z |generic_unit_system.length)
self.assertAlmostEqual(result[0].value_in(generic_unit_system.length/generic_unit_system.time**2), -M/(r+a)**2 * x/r, places=14)
self.assertAlmostEqual(result[0],result[2]/3, places=14)
scaleM=2.345678|units.MSun
scalea=7.654321|units.parsec
converter=nbody_system.nbody_to_si(scaleM, scalea)
instance = Agama(converter, type="Dehnen", mass=M*scaleM, scaleradius=a*scalea)
result=instance.get_gravity_at_point(
0.|generic_unit_system.length, x*scalea, y*scalea, z*scalea)
scale=M/(r+a)**2 *scaleM/scalea**2*constants.G
self.assertAlmostEqual(result[0], scale * x/r, places=10)
instance.stop()
def test2(self):
particles=new_plummer_model(10000)
instance = Agama(type="Multipole", points=particles)
result=instance.get_potential_at_point(
0.|generic_unit_system.length,
0.|generic_unit_system.length,
0.|generic_unit_system.length,
0.|generic_unit_system.length)
self.assertLess(abs(result/(-16./3/3.1416| generic_unit_system.length**2/generic_unit_system.time**2) - 1), 0.04)
scaleM=1234|units.MSun
scaleR=5.6 |units.parsec
converter=nbody_system.nbody_to_si(scaleM,scaleR)
particles=new_plummer_model(20000, convert_nbody=converter)
instance = Agama(converter, type="Multipole", points=particles)
x=3.|units.parsec
y=4.|units.parsec
z=5.|units.parsec
r=(x*x+y*y+z*z)**0.5
result=instance.get_gravity_at_point(0|units.parsec, x, y, z)
expected=-constants.G*scaleM/(r*r+(3*3.1416/16*scaleR)**2)**1.5*x
self.assertLess(abs(result[0]/expected-1), 0.03)
self.assertLess(abs(result[2]/result[0]-z/x), 0.03)
Rinit = 50. | units.parsec
timestep = 0.01 | units.Myr
Mcluster = 4.e4 | units.MSun
Rcluster = 0.7 | units.parsec
converter = nbody_system.nbody_to_si(Mcluster, Rcluster)
# create a globular cluster model
particles = new_king_model(N, W0, convert_nbody=converter)
particles.radius = 0.0 | units.parsec
cluster = Hermite(converter,
parameters=[("epsilon_squared", (0.01 | units.parsec)**2)
],
channel_type='sockets')
# create the external potential of the Galaxy
galaxy = Agama(converter, type="Dehnen", gamma=1.8, \
rscale=1000.| units.parsec, mass=1.6e10 | units.MSun, channel_type='sockets')
# shift the cluster to an orbit around Galactic center
acc, _, _ = galaxy.get_gravity_at_point(0 | units.kpc, Rinit,
0 | units.kpc, 0 | units.kpc)
vcirc = (-acc * Rinit)**0.5
print("Vcirc=%f km/s" % vcirc.value_in(units.kms))
particles.x += Rinit
particles.vy += vcirc
cluster.particles.add_particles(particles)
# set up bridge; cluster is evolved under influence of the galaxy
sys = bridge(verbose=False)
sys.add_system(cluster, (galaxy, ), False)
# evolve and make plots
# set up parameters:
N = 100
W0 = 3
Rinit = 50. | units.parsec
timestep = 0.01 | units.Myr
Mcluster = 4.e4 | units.MSun
Rcluster = 0.7 | units.parsec
converter = nbody_system.nbody_to_si(Mcluster,Rcluster)
# create a globular cluster model
particles = new_king_model(N, W0, convert_nbody=converter)
particles.radius = 0.0| units.parsec
cluster = PhiGRAPE(converter, parameters=[("epsilon_squared", (0.01 | units.parsec)**2)])
# create the external potential of the Galaxy
galaxy = Agama(converter, type="Dehnen", gamma=1.8, \
rscale=1000.| units.parsec, mass=1.6e10 | units.MSun, channel_type='sockets')
# shift the cluster to an orbit around Galactic center
acc,_,_ = galaxy.get_gravity_at_point(0|units.kpc, Rinit, 0|units.kpc, 0|units.kpc)
vcirc = (-acc * Rinit)**0.5
print "Vcirc=", vcirc.value_in(units.kms), "km/s"
particles.x += Rinit
particles.vy += vcirc
cluster.particles.add_particles(particles)
# set up bridge; cluster is evolved under influence of the galaxy
sys = bridge(verbose=False)
sys.add_system(cluster, (galaxy,), False)
# evolve and make plots
times = units.Myr([0.,0.2,0.4,0.6,0.8,1.0,1.2,1.4])
mass_max=20 | units.MSun,
alpha=-2.5)
Mcluster = masses.sum()
converter = nbody_system.nbody_to_si(Mcluster, Rcluster)
particles = new_plummer_model(N, converter)
particles.mass = masses
stellarevol = SeBa(redirection='null')
stellarevol.particles.add_particles(particles)
particles.radius = stellarevol.particles.radius
if useRaga:
cluster = Agama(converter,
redirection='none',
number_of_workers=8,
updatepotential=True,
coulombLog=5.0,
filelog='raga_multimass_plummer.log',
fileoutputpotential='raga_multimass_plummer.pot',
fileoutputrelaxation='raga_multimass_plummer.rel',
fileoutput='raga_multimass_plummer.out',
fileoutputformat='nemo',
outputinterval=1. | units.Myr,
numSamplesPerEpisode=10) #, particles=particles)
else:
#cluster = ph4(converter, channel_type='sockets', number_of_workers=8, parameters=[("epsilon_squared", (0.01 | units.parsec)**2)])
cluster = ph4(converter,
channel_type='sockets',
mode='gpu',
parameters=[("epsilon_squared", (0.01 | units.parsec)**2)
])
#cluster = Gadget2(converter, channel_type='sockets', number_of_workers=8, parameters=[("epsilon_squared", (0.01 | units.parsec)**2)], redirection='null')
#cluster = Bonsai(converter, channel_type='sockets', parameters=[("epsilon_squared", (0.01 | units.parsec)**2)], redirection='null')
cluster.particles.add_particles(particles)
