def crash_test(method=1):
code=Kepler(redirection="none")
code.set_method(method)
smu=1.224744871391589
mu=smu**2
r0=2.787802728537455
rv0=-0.9899959571994231
alpha=0.01380749549277993
smudt=2.809925892593303
v02=(mu*(2/r0-alpha))
vx=rv0
vy=(v02-vx**2)**0.5
sun=Particle()
sun.mass=mu | nbody_system.mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=r0| nbody_system.length
comet.y=0. | nbody_system.length
comet.z=0. | nbody_system.length
comet.vx=vx | nbody_system.speed
comet.vy=vy | nbody_system.speed
comet.vz=0. | nbody_system.speed
tend=(smudt/smu) | nbody_system.time
print tend
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def test_kepler(N=10000, tend=1.| units.yr,method=0):
numpy.random.seed(12345)
conv=nbody_system.nbody_to_si(2.| units.MSun, 5.|units.AU)
comets=new_plummer_model(N,conv)
sun=Particle(mass=1.|units.MSun)
sun.position=[0,0,0]|units.AU
sun.velocity=[0,0,0]|units.kms
comets.mass*=0.
code=Kepler(conv,redirection="none")
code.set_method(method)
code.central_particle.add_particle(sun)
code.orbiters.add_particles(comets)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz)
# print code.orbiters.x[0]
print orbital_elements_from_binary(code.particles[0:2],constants.G)
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2],constants.G)
# print code.orbiters.x[0]
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
dev=numpy.where(da > 0.00001)[0]
print len(dev)
print a0[dev].value_in(units.AU)
print eps0[dev]
# pyplot.plot(a0[dev].value_in(units.AU),eps0[dev],"ro")
# pyplot.plot(a[dev].value_in(units.AU),eps[dev],"g+")
print "max da,deps:",da.max(), deps.max()
print "time:",t2-t1
# pyplot.show()
return t2-t1,da.max(),deps.max()
def test_kepler_parabolic( tend=1,method=0, sign=+1):
code=Kepler(redirection="none")
code.set_method(method)
sun=Particle()
sun.mass=1. | nbody_system.mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=1. | nbody_system.length
comet.y=0. | nbody_system.length
comet.z=0. | nbody_system.length
comet.vx=0. | nbody_system.speed
comet.vy=(1.0 + sign * 1.0e-10)*(2*nbody_system.G*sun.mass/comet.x)**0.5
comet.vz=0. | nbody_system.speed
tend=tend | nbody_system.time
print tend
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def test_kepler_almost_parabolic( tend=1,method=0):
code=Kepler(redirection="none")
code.set_method(method)
mass1=1.| nbody_system.mass
mass2=0| nbody_system.mass
semimajor_axis=1.|nbody_system.length
eccentricity=0.9999999
p=2*numpy.pi*(semimajor_axis**3/nbody_system.G/mass1)**0.5
tend=tend*p
print tend
parts=new_binary_from_orbital_elements(
mass1,
mass2,
semimajor_axis,
eccentricity = eccentricity,
true_anomaly = 0.0102121
)
code.central_particle.add_particle(parts[0])
code.orbiters.add_particle(parts[1])
a0,eps0=elements(mass1,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(mass1,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def t_linear(tend=1,N=100,method=0):
code=Kepler(redirection="none")
code.set_method(method)
mass=1. | nbody_system.mass
x=1. | nbody_system.length
vx=0 | nbody_system.speed
e=0.5*vx**2-nbody_system.G*mass/x
semimajor_axis=-nbody_system.G*mass/2/e
p=2*numpy.pi*(semimajor_axis**3/nbody_system.G/mass)**0.5
print semimajor_axis
print p
tend=tend*p
dt=p/N
sun=Particle()
sun.mass=mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=x
comet.y=0. | nbody_system.length
comet.z=0. | nbody_system.length
comet.vx=vx
comet.vy=0. | nbody_system.speed
comet.vz=0. | nbody_system.speed
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
#pyplot.ion()
#f=pyplot.figure(figsize=(8,6))
#pyplot.show()
tnow=0*tend
time=[]
xs=[]
while tnow<tend:
tnow+=dt
print tnow,int(tnow/dt)
code.evolve_model(tnow)
#f.clf()
time.append(tnow/tend)
xs.append(code.orbiters.x[0].number)
#pyplot.plot(time,xs,"r+")
#pyplot.xlim(-0.1,1.1)
#pyplot.ylim(-1.1,3.1)
#pyplot.draw()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
raw_input()
def test_softening(method=1):
code=Kepler(redirection="none")
code.set_method(method)
dt=float.fromhex("0x1.67b39e372f04dp+4")
mu=float.fromhex("0x1.fffffffffffdfp-3")
e2=float.fromhex("0x1.0000000000003p+0")
pos1=float.fromhex("0x1.1b76542265052p-1")
pos2=float.fromhex("0x1.0c4dbda42097cp-6")
pos3=float.fromhex("0x1.54fd66cd1e212p-3")
vel1=float.fromhex("0x1.d6ef43d58ca7ep-2")
vel2=float.fromhex("0x1.7a85379e59794p-2")
vel3=float.fromhex("-0x1.5421044d1acffp-1")
sun=Particle()
sun.mass=mu | nbody_system.mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=pos1 | nbody_system.length
comet.y=pos2 | nbody_system.length
comet.z=pos3 | nbody_system.length
comet.vx=vel1 | nbody_system.speed
comet.vy=vel2 | nbody_system.speed
comet.vz=vel3 | nbody_system.speed
tend=dt | nbody_system.time
print tend,mu
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
code.parameters.epsilon_squared = e2 | nbody_system.length**2
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1
def crash_test2(method=1):
code=Kepler(redirection="none")
code.set_method(method)
"""
mu=struct.unpack('!d','3ff7ffffffffffff'.decode('hex'))[0]
dt=struct.unpack('!d','40025ab746b00001'.decode('hex'))[0]
pos1=struct.unpack('!d','bfed36dc82998ed4'.decode('hex'))[0]
pos2=struct.unpack('!d','40051297fc6e5256'.decode('hex'))[0]
pos3=struct.unpack('!d','0000000000000000'.decode('hex'))[0]
vel1=struct.unpack('!d','3fb09d8008ba33b9'.decode('hex'))[0]
vel2=struct.unpack('!d','bff06788b551b81d'.decode('hex'))[0]
vel3=struct.unpack('!d','0000000000000000'.decode('hex'))[0]
"""
mu=float.fromhex("0x1.8p+0")
dt=float.fromhex("0x1.25ab746bp+1")
pos1=float.fromhex("-0x1.d36dc82998ed4p-1")
pos2=float.fromhex("0x1.51297fc6e5256p+1")
pos3=float.fromhex("0x0p+0")
vel1=float.fromhex("0x1.09d8008ba33b9p-4")
vel2=float.fromhex("-0x1.06788b551b81ep+0")
vel3=float.fromhex("0x0p+0")
sun=Particle()
sun.mass=mu | nbody_system.mass
sun.x=0. | nbody_system.length
sun.y=0. | nbody_system.length
sun.z=0. | nbody_system.length
sun.vx=0. | nbody_system.speed
sun.vy=0. | nbody_system.speed
sun.vz=0. | nbody_system.speed
comet=Particle()
comet.mass= 0 | nbody_system.mass
comet.x=pos1 | nbody_system.length
comet.y=pos2 | nbody_system.length
comet.z=pos3 | nbody_system.length
comet.vx=vel1 | nbody_system.speed
comet.vy=vel2 | nbody_system.speed
comet.vz=vel3 | nbody_system.speed
tend=dt | nbody_system.time
print tend,mu
code.central_particle.add_particle(sun)
code.orbiters.add_particle(comet)
a0,eps0=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
print orbital_elements_from_binary(code.particles[0:2])
t1=time.time()
code.evolve_model(tend)
t2=time.time()
print orbital_elements_from_binary(code.particles[0:2])
print code.orbiters.position
a,eps=elements(sun.mass,code.orbiters.x,code.orbiters.y,code.orbiters.z,
code.orbiters.vx,code.orbiters.vy,code.orbiters.vz,G=nbody_system.G)
da=abs((a-a0)/a0)
deps=abs(eps-eps0)/eps0
print da,deps
print "time:",t2-t1