def simulation(par):
    anom, dt, e, integrator = par

    e = 1. - pow(10., e)
    dt = pow(10., dt) * torb

    rebound.reset()
    rebound.integrator = integrator
    rebound.force_is_velocitydependent = 0
    rebound.dt = dt

    rebound.add(m=1.)
    rebound.add(m=0., x=(1. - e), vy=np.sqrt((1. + e) / (1. - e)))
    particles = rebound.particles

    Ei = -1. / np.sqrt(particles[1].x * particles[1].x + particles[1].y *
                       particles[1].y + particles[1].z * particles[1].z
                       ) + 0.5 * (particles[1].vx * particles[1].vx +
                                  particles[1].vy * particles[1].vy +
                                  particles[1].vz * particles[1].vz)

    rebound.integrate(tmax, exactFinishTime=0, keepSynchronized=1)

    Ef = -1. / np.sqrt(particles[1].x * particles[1].x + particles[1].y *
                       particles[1].y + particles[1].z * particles[1].z
                       ) + 0.5 * (particles[1].vx * particles[1].vx +
                                  particles[1].vy * particles[1].vy +
                                  particles[1].vz * particles[1].vz)

    return [
        float(rebound.iter) / rebound.t * dt,
        np.fabs((Ef - Ei) / Ei) + 1e-16,
        rebound.timing / rebound.t * dt * 1e6 / 2., (Ef - Ei) / Ei
    ]
def simulation(par):
    saturn_a, saturn_e = par
    rebound.reset()
    rebound.integrator = "whfast-nocor"
    rebound.min_dt = 5.
    rebound.dt = 1.

    # These parameters are only approximately those of Jupiter and Saturn.
    sun = rebound.Particle(m=1.)
    rebound.add(sun)
    jupiter = rebound.add(primary=sun,
                          m=0.000954,
                          a=5.204,
                          anom=0.600,
                          omega=0.257,
                          e=0.048)
    saturn = rebound.add(primary=sun,
                         m=0.000285,
                         a=saturn_a,
                         anom=0.871,
                         omega=1.616,
                         e=saturn_e)

    rebound.move_to_com()
    rebound.init_megno(1e-16)
    rebound.integrate(1e3 * 2. * np.pi)

    return [
        rebound.calculate_megno(),
        1. / (rebound.calculate_lyapunov() * 2. * np.pi)
    ]  # returns MEGNO and Lypunov timescale in years
def simulation(par):
    saturn_a, saturn_e = par
    rebound.reset()
    rebound.integrator = "whfast-nocor"
    rebound.dt = 5.
    
    # These parameters are only approximately those of Jupiter and Saturn.
    rebound.add(m=1.)
    rebound.add(m=0.000954, a=5.204, anom=0.600, omega=0.257, e=0.048)
    rebound.add(m=0.000285, a=saturn_a, anom=0.871, omega=1.616, e=saturn_e)

    rebound.move_to_com()
    rebound.init_megno(1e-16)
    rebound.integrate(5e2*2.*np.pi) # integrator for 500 years

    return [rebound.calculate_megno(),1./(rebound.calculat_lyapunov()*2.*np.pi)] # returns MEGNO and Lypunov timescale in years
Example #4
0
def simulation(par):
    saturn_a, saturn_e = par
    rebound.reset()
    rebound.set_min_dt(0.1)
    
    # These parameters are only approximately those of Jupiter and Saturn.
    sun     = rebound.Particle(m=1.)
    rebound.particle_add(sun)
    jupiter = rebound.particle_add(primary=sun,m=0.000954, a=5.204, anom=0.600, omega=0.257, e=0.048)
    saturn  = rebound.particle_add(primary=sun,m=0.000285, a=saturn_a, anom=0.871, omega=1.616, e=saturn_e)

    rebound.move_to_center_of_momentum()
    rebound.megno_init(1e-16)
    rebound.integrate(1e4*2.*np.pi)

    return [rebound.get_megno(),1./(rebound.get_lyapunov()*2.*np.pi)] # returns MEGNO and Lypunov timescale in years
Example #5
0
def simulation(integrator):
    print("Running "+integrator)
    with open(integrator+".txt","w") as f:
        rebound.reset()
        rebound.set_integrator(integrator)
        rebound.set_dt(0.2)
            
        rebound.add_particle(m=1.)
        rebound.add_particle(m=0.01, a=1,e=0.1)
        rebound.add_particle(m=0.01, a=2.)

        rebound.move_to_center_of_momentum()
        rebound.init_megno(1e-10)
        particles = rebound.get_particles()
        times = np.logspace(2,5,num=1000)
        for t in times:
            rebound.integrate(t,0)
            print("%e %e %e %e %e %e %e %e\n" %(rebound.get_t(), rebound.get_megno(), particles[0].x, particles[1].x, particles[2].x, particles[3].x, particles[4].x, particles[5].x),file=f)
Example #6
0
def simulation(integrator):
    print("Running "+integrator)
    with open(integrator+".txt","w") as f:
        rebound.reset()
        rebound.integrator = integrator
        rebound.dt = 0.2
            
        rebound.add(m=1.)
        rebound.add(m=0.01, a=1,e=0.1)
        rebound.add(m=0.01, a=2.)

        rebound.move_to_com()
        rebound.init_megno(1e-10)
        particles = rebound.particles
        times = np.logspace(2,5,num=1000)
        for t in times:
            rebound.integrate(t,0)
            print("%e %e %e %e %e %e %e %e\n" %(rebound.t, rebound.calculate_megno(), particles[0].x, particles[1].x, particles[2].x, particles[3].x, particles[4].x, particles[5].x),file=f)
def simulation(par):
    saturn_a, saturn_e = par
    rebound.reset()
    rebound.integrator = "whfast-nocor"
    rebound.min_dt = 5.
    rebound.dt = 1.
    
    # These parameters are only approximately those of Jupiter and Saturn.
    sun     = rebound.Particle(m=1.)
    rebound.add(sun)
    jupiter = rebound.add(primary=sun,m=0.000954, a=5.204, anom=0.600, omega=0.257, e=0.048)
    saturn  = rebound.add(primary=sun,m=0.000285, a=saturn_a, anom=0.871, omega=1.616, e=saturn_e)

    rebound.move_to_com()
    rebound.init_megno(1e-16)
    rebound.integrate(1e3*2.*np.pi)

    return [rebound.calculate_megno(),1./(rebound.calculate_lyapunov()*2.*np.pi)] # returns MEGNO and Lypunov timescale in years
Example #8
0
def simulation(par):
    saturn_a, saturn_e = par
    rebound.reset()
    rebound.integrator = "whfast-nocor"
    rebound.dt = 5.

    # These parameters are only approximately those of Jupiter and Saturn.
    rebound.add(m=1.)
    rebound.add(m=0.000954, a=5.204, anom=0.600, omega=0.257, e=0.048)
    rebound.add(m=0.000285, a=saturn_a, anom=0.871, omega=1.616, e=saturn_e)

    rebound.move_to_com()
    rebound.init_megno(1e-16)
    rebound.integrate(5e2 * 2. * np.pi)  # integrator for 500 years

    return [
        rebound.calculate_megno(),
        1. / (rebound.calculat_lyapunov() * 2. * np.pi)
    ]  # returns MEGNO and Lypunov timescale in years
Example #9
0
def simulation(par):
    anom, dt, e, integrator = par

    e = 1.-pow(10.,e)
    dt = pow(10.,dt)*torb

    rebound.reset()
    rebound.set_integrator(integrator)
    rebound.set_force_is_velocitydependent(0)
    rebound.set_dt(dt)

    rebound.add_particle(m=1.)
    rebound.add_particle(m=0., x=(1.-e), vy=np.sqrt((1.+e)/(1.-e)))
    particles = rebound.get_particles()
    
    Ei = -1./np.sqrt(particles[1].x*particles[1].x+particles[1].y*particles[1].y+particles[1].z*particles[1].z) + 0.5 * (particles[1].vx*particles[1].vx+particles[1].vy*particles[1].vy+particles[1].vz*particles[1].vz)

    rebound.integrate(tmax,exactFinishTime=0,keepSynchronized=1)
    
    Ef = -1./np.sqrt(particles[1].x*particles[1].x+particles[1].y*particles[1].y+particles[1].z*particles[1].z) + 0.5 * (particles[1].vx*particles[1].vx+particles[1].vy*particles[1].vy+particles[1].vz*particles[1].vz)

    return [float(rebound.get_iter())/rebound.get_t()*dt, np.fabs((Ef-Ei)/Ei)+1e-16, rebound.get_timing()/rebound.get_t()*dt*1e6/2., (Ef-Ei)/Ei]
def simulation(par):
    anom, dt, e, integrator = par

    e = 1.-pow(10.,e)
    dt = pow(10.,dt)*torb

    rebound.reset()
    rebound.integrator = integrator
    rebound.force_is_velocitydependent = 0
    rebound.dt = dt

    rebound.add(m=1.)
    rebound.add(m=0., x=(1.-e), vy=np.sqrt((1.+e)/(1.-e)))
    particles = rebound.particles
    
    Ei = -1./np.sqrt(particles[1].x*particles[1].x+particles[1].y*particles[1].y+particles[1].z*particles[1].z) + 0.5 * (particles[1].vx*particles[1].vx+particles[1].vy*particles[1].vy+particles[1].vz*particles[1].vz)

    rebound.integrate(tmax,exactFinishTime=0,keepSynchronized=1)
    
    Ef = -1./np.sqrt(particles[1].x*particles[1].x+particles[1].y*particles[1].y+particles[1].z*particles[1].z) + 0.5 * (particles[1].vx*particles[1].vx+particles[1].vy*particles[1].vy+particles[1].vz*particles[1].vz)

    return [float(rebound.iter)/rebound.t*dt, np.fabs((Ef-Ei)/Ei)+1e-16, rebound.timing/rebound.t*dt*1e6/2., (Ef-Ei)/Ei]
Example #11
0
def simulation(integrator):
    print("Running " + integrator)
    with open(integrator + ".txt", "w") as f:
        rebound.reset()
        rebound.integrator = integrator
        rebound.dt = 0.2

        rebound.add(m=1.)
        rebound.add(m=0.01, a=1, e=0.1)
        rebound.add(m=0.01, a=2.)

        rebound.move_to_com()
        rebound.init_megno(1e-10)
        particles = rebound.particles
        times = np.logspace(2, 5, num=1000)
        for t in times:
            rebound.integrate(t, 0)
            print("%e %e %e %e %e %e %e %e\n" %
                  (rebound.t, rebound.calculate_megno(), particles[0].x,
                   particles[1].x, particles[2].x, particles[3].x,
                   particles[4].x, particles[5].x),
                  file=f)
Example #12
0
def simulation(par):
    S, dt,e0 = par

    rebound.reset()
    rebound.set_integrator("wh")
    #rebound.set_integrator("whfast")
    rebound.set_dt(dt)

    rebound.particle_add(m=1.)
    rebound.particle_add(m=0.,a=1.,e=e0)

    #rebound.move_to_center_of_momentum()
    #rebound.megno_init(1.e-16)


    particles = rebound.particles_get()
    def starkforce(): # need to put inside simulation(par) to have access to S and particles
        particles[1].ax += -S

    rebound.set_additional_forces(starkforce)

    rebound.integrate(50000.*np.pi)

    return [rebound.get_megno(), rebound.get_t()]
Example #13
0
# Import the rebound module
import sys; sys.path.append('../')
import rebound
from rebound import Particle
import numpy as np
from interruptible_pool import InterruptiblePool


for i in np.linspace(-2.*np.pi,2.*np.pi,1000):
    rebound.reset()
    rebound.set_integrator("whfast-nocor")
    rebound.set_dt(0.01*2.*np.pi)

    try:
        rebound.particle_add(m=1.)
        rebound.particle_add(m=0., a=1., e=1.01, anom=i)
        particles = rebound.particles_get()
        print particles[1].x, particles[1].y, i
        #rebound.step()
        #print particles[1].x, particles[1].y, i
    except:
        pass
    
Example #14
0
def simulation(par):
    integrator = par
    rebound.reset()
    k = 0.01720209895    
    G = k*k
    rebound.set_G(G)     
    rebound.set_dt(dt)
    rebound.set_integrator(integrator)

    rebound.add_particle(m=1.00000597682, x=-4.06428567034226e-3, y=-6.08813756435987e-3, z=-1.66162304225834e-6, vx=+6.69048890636161e-6, vy=-6.33922479583593e-6, vz=-3.13202145590767e-9)   # Sun
    rebound.add_particle(m=1./1047.355,   x=+3.40546614227466e+0, y=+3.62978190075864e+0, z=+3.42386261766577e-2, vx=-5.59797969310664e-3, vy=+5.51815399480116e-3, vz=-2.66711392865591e-6)   # Jupiter
#    rebound.add_particle(m=1./3501.6,     x=+6.60801554403466e+0, y=+6.38084674585064e+0, z=-1.36145963724542e-1, vx=-4.17354020307064e-3, vy=+3.99723751748116e-3, vz=+1.67206320571441e-5)   # Saturn
#    rebound.add_particle(m=1./22869.,     x=+1.11636331405597e+1, y=+1.60373479057256e+1, z=+3.61783279369958e-1, vx=-3.25884806151064e-3, vy=+2.06438412905916e-3, vz=-2.17699042180559e-5)   # Uranus
#    rebound.add_particle(m=1./19314.,     x=-3.01777243405203e+1, y=+1.91155314998064e+0, z=-1.53887595621042e-1, vx=-2.17471785045538e-4, vy=-3.11361111025884e-3, vz=+3.58344705491441e-5)   # Neptune
#    rebound.add_particle(m=0,             x=-2.13858977531573e+1, y=+3.20719104739886e+1, z=+2.49245689556096e+0, vx=-1.76936577252484e-3, vy=-2.06720938381724e-3, vz=+6.58091931493844e-4)   # Pluto
    N = rebound.get_N()

    def move_to_heliocentric():
        particles = rebound.get_particles()
        
        for i in xrange(1,N):
            particles[i].x -= particles[0].x
            particles[i].y -= particles[0].y
            particles[i].z -= particles[0].z
            particles[i].vx -= particles[0].vx
            particles[i].vy -= particles[0].vy
            particles[i].vz -= particles[0].vz
        particles[0].x  = 0.
        particles[0].y  = 0. 
        particles[0].z  = 0. 
        particles[0].vx = 0. 
        particles[0].vy = 0. 
        particles[0].vz = 0. 


    def energy():
        if integrator=="wh":
            rebound.move_to_center_of_momentum()
        particles = rebound.get_particles()
        E_kin = 0.
        E_pot = 0.
        for i in xrange(N):
            E_kin += 0.5*particles[i].m*(particles[i].vx*particles[i].vx + particles[i].vy*particles[i].vy + particles[i].vz*particles[i].vz)
            for j in xrange(i+1,N):
                dx = particles[i].x-particles[j].x
                dy = particles[i].y-particles[j].y
                dz = particles[i].z-particles[j].z
                r2 = dx*dx + dy*dy + dz*dz
                E_pot -= G*particles[i].m*particles[j].m/np.sqrt(r2)
        if integrator=="wh":
            move_to_heliocentric()
        return E_kin+E_pot

    rebound.move_to_center_of_momentum()

    es = []

    ei = energy()
    for time in xrange(Nsteps):
        rebound.step()
        ef = energy()
        e = (ei-ef)
        es.append(e)
        ei = ef

    es = np.array(es)
    print integrator + " done."
    return [es]
Example #15
0
def simulation(par):
    integrator, run, trial = par
    rebound.reset()
    k = 0.01720209895    
    Gfac = 1./k
    rebound.set_dt(dt)
    rebound.set_integrator(integrator)
    rebound.set_force_is_velocitydependent(0)

    massfac = 1.
    rebound.add_particle(m=1.00000597682, x=-4.06428567034226e-3, y=-6.08813756435987e-3, z=-1.66162304225834e-6,      vx=+6.69048890636161e-6*Gfac, vy=-6.33922479583593e-6*Gfac, vz=-3.13202145590767e-9*Gfac)   # Sun
    rebound.add_particle(m=massfac/1407.355,   x=+3.40546614227466e+0, y=+3.62978190075864e+0, z=+3.42386261766577e-2, vx=-5.59797969310664e-3*Gfac, vy=+5.51815399480116e-3*Gfac, vz=-2.66711392865591e-6*Gfac)   # Jupiter
    rebound.add_particle(m=massfac/3501.6,     x=+6.60801554403466e+0, y=+6.38084674585064e+0, z=-1.36145963724542e-1, vx=-4.17354020307064e-3*Gfac, vy=+3.99723751748116e-3*Gfac, vz=+1.67206320571441e-5*Gfac)   # Saturn
    rebound.add_particle(m=massfac/22869.,     x=+1.11636331405597e+1, y=+1.60373479057256e+1, z=+3.61783279369958e-1, vx=-3.25884806151064e-3*Gfac, vy=+2.06438412905916e-3*Gfac, vz=-2.17699042180559e-5*Gfac)   # Uranus
    rebound.add_particle(m=massfac/19314.,     x=-3.01777243405203e+1, y=+1.91155314998064e+0, z=-1.53887595621042e-1, vx=-2.17471785045538e-4*Gfac, vy=-3.11361111025884e-3*Gfac, vz=+3.58344705491441e-5*Gfac)   # Neptune
    N = rebound.get_N()
    particles = rebound.get_particles()
    np.random.seed(run)
    for i in xrange(N):
        particles[i].m *= 1.+1e-3*np.random.rand()
        particles[i].x *= 1.+1e-3*np.random.rand()
        particles[i].y *= 1.+1e-3*np.random.rand()
        particles[i].z *= 1.+1e-3*np.random.rand()
        particles[i].vx *= 1.+1e-3*np.random.rand()
        particles[i].vy *= 1.+1e-3*np.random.rand()
        particles[i].vz *= 1.+1e-3*np.random.rand()

    def move_to_heliocentric():
        particles = rebound.get_particles()
        
        particles[0].x  = 0.
        particles[0].y  = 0. 
        particles[0].z  = 0. 
        particles[0].vx = 0. 
        particles[0].vy = 0. 
        particles[0].vz = 0. 


    def energy():
        particles = rebound.get_particles()
        com_vx = 0.
        com_vy = 0.
        com_vz = 0.
        if integrator=="wh" or integrator=="mercury" or integrator[0:7]=="swifter":
            mtot = 0.
            for i in xrange(0,N):
                com_vx += particles[i].vx*particles[i].m 
                com_vy += particles[i].vy*particles[i].m 
                com_vz += particles[i].vz*particles[i].m 
                mtot += particles[i].m
            com_vx /= mtot
            com_vy /= mtot
            com_vz /= mtot
        E_kin = 0.
        E_pot = 0.
        for i in xrange(N):
            dvx = particles[i].vx - com_vx
            dvy = particles[i].vy - com_vy
            dvz = particles[i].vz - com_vz
            E_kin += 0.5*particles[i].m*(dvx*dvx + dvy*dvy + dvz*dvz)
            for j in xrange(i+1,N):
                dx = particles[i].x-particles[j].x
                dy = particles[i].y-particles[j].y
                dz = particles[i].z-particles[j].z
                r2 = dx*dx + dy*dy + dz*dz
                E_pot -= particles[i].m*particles[j].m/np.sqrt(r2)
        return E_kin+E_pot

    times = np.logspace(np.log10(orbit),np.log10(tmax),Ngrid)
    if integrator=="wh" or integrator=="mercury" or integrator[0:7]=="swifter":
        move_to_heliocentric()
    else:
        rebound.move_to_center_of_momentum()
    ei = energy()

    es = []

    runtime = 0.
    for t in times:
        rebound.integrate(t,exactFinishTime=0,keepSynchronized=0)
        ef = energy()
        e = np.fabs((ei-ef)/ei)+1.1e-16
        es.append(e)
        runtime += rebound.get_timing()
    
    integrator, run, trial = par
    print integrator.ljust(13) + " %9.5fs"%(runtime) + "\t Error: %e"  %( e)
    
    es = np.array(es)
    return [times, es]
def simulation(par):
    import rebound
    integrator, dt, run = par
    rebound.reset()
    k = 0.01720209895
    G = k * k
    rebound.G = G
    rebound.dt = dt
    rebound.integrator = integrator
    rebound.force_is_velocitydependent = 0

    rebound.add(m=1.00000597682,
                x=-4.06428567034226e-3,
                y=-6.08813756435987e-3,
                z=-1.66162304225834e-6,
                vx=+6.69048890636161e-6,
                vy=-6.33922479583593e-6,
                vz=-3.13202145590767e-9)  # Sun
    rebound.add(m=1. / 1407.355,
                x=+3.40546614227466e+0,
                y=+3.62978190075864e+0,
                z=+3.42386261766577e-2,
                vx=-5.59797969310664e-3,
                vy=+5.51815399480116e-3,
                vz=-2.66711392865591e-6)  # Jupiter
    rebound.add(m=1. / 3501.6,
                x=+6.60801554403466e+0,
                y=+6.38084674585064e+0,
                z=-1.36145963724542e-1,
                vx=-4.17354020307064e-3,
                vy=+3.99723751748116e-3,
                vz=+1.67206320571441e-5)  # Saturn
    rebound.add(m=1. / 22869.,
                x=+1.11636331405597e+1,
                y=+1.60373479057256e+1,
                z=+3.61783279369958e-1,
                vx=-3.25884806151064e-3,
                vy=+2.06438412905916e-3,
                vz=-2.17699042180559e-5)  # Uranus
    rebound.add(m=1. / 19314.,
                x=-3.01777243405203e+1,
                y=+1.91155314998064e+0,
                z=-1.53887595621042e-1,
                vx=-2.17471785045538e-4,
                vy=-3.11361111025884e-3,
                vz=+3.58344705491441e-5)  # Neptune
    N = rebound.N
    particles = rebound.particles
    np.random.seed(run)
    for i in xrange(N):
        particles[i].m *= 1. + 1e-3 * np.random.rand()
        particles[i].x *= 1. + 1e-3 * np.random.rand()
        particles[i].y *= 1. + 1e-3 * np.random.rand()
        particles[i].z *= 1. + 1e-3 * np.random.rand()
        particles[i].vx *= 1. + 1e-3 * np.random.rand()
        particles[i].vy *= 1. + 1e-3 * np.random.rand()
        particles[i].vz *= 1. + 1e-3 * np.random.rand()

    def move_to_heliocentric():
        particles[0].x = 0.
        particles[0].y = 0.
        particles[0].z = 0.
        particles[0].vx = 0.
        particles[0].vy = 0.
        particles[0].vz = 0.

    def energy():
        com_vx = 0.
        com_vy = 0.
        com_vz = 0.
        if integrator == "wh" or integrator == "mercury" or integrator[
                0:7] == "swifter":
            mtot = 0.
            for i in xrange(0, N):
                com_vx += particles[i].vx * particles[i].m
                com_vy += particles[i].vy * particles[i].m
                com_vz += particles[i].vz * particles[i].m
                mtot += particles[i].m
            com_vx /= mtot
            com_vy /= mtot
            com_vz /= mtot
        E_kin = 0.
        E_pot = 0.
        for i in xrange(N):
            dvx = particles[i].vx - com_vx
            dvy = particles[i].vy - com_vy
            dvz = particles[i].vz - com_vz
            E_kin += 0.5 * particles[i].m * (dvx * dvx + dvy * dvy + dvz * dvz)
            for j in xrange(i + 1, N):
                dx = particles[i].x - particles[j].x
                dy = particles[i].y - particles[j].y
                dz = particles[i].z - particles[j].z
                r2 = dx * dx + dy * dy + dz * dz
                E_pot -= G * particles[i].m * particles[j].m / np.sqrt(r2)
        return E_kin + E_pot

    if integrator == "wh" or integrator == "mercury" or integrator[
            0:7] == "swifter":
        move_to_heliocentric()
    else:
        rebound.move_to_com()
    ei = energy()

    runtime = 0.
    rebound.integrate(tmax, exactFinishTime=0)
    ef = energy()
    e = np.fabs((ei - ef) / ei) + 1.1e-16
    runtime += rebound.timing

    integrator, dt, run = par
    print integrator.ljust(13) + " %9.5fs" % (runtime) + "\t Error: %e" % (e)
    return [runtime, e]
def simulation(par):
    integrator, mass = par
    rebound.reset()
    mass = pow(10., mass)
    k = 0.01720209895
    G = k * k
    rebound.G = G
    rebound.dt = 0.
    rebound.integrator = integrator

    rebound.add(m=1.00000597682,
                x=-4.06428567034226e-3,
                y=-6.08813756435987e-3,
                z=-1.66162304225834e-6,
                vx=+6.69048890636161e-6,
                vy=-6.33922479583593e-6,
                vz=-3.13202145590767e-9)  # Sun
    rebound.add(m=mass,
                x=+3.40546614227466e+0,
                y=+3.62978190075864e+0,
                z=+3.42386261766577e-2,
                vx=-5.59797969310664e-3,
                vy=+5.51815399480116e-3,
                vz=-2.66711392865591e-6)  # Jupiter
    rebound.add(m=mass,
                x=+6.60801554403466e+0,
                y=+6.38084674585064e+0,
                z=-1.36145963724542e-1,
                vx=-4.17354020307064e-3,
                vy=+3.99723751748116e-3,
                vz=+1.67206320571441e-5)  # Saturn
    rebound.add(m=mass,
                x=+1.11636331405597e+1,
                y=+1.60373479057256e+1,
                z=+3.61783279369958e-1,
                vx=-3.25884806151064e-3,
                vy=+2.06438412905916e-3,
                vz=-2.17699042180559e-5)  # Uranus
    rebound.add(m=mass,
                x=-3.01777243405203e+1,
                y=+1.91155314998064e+0,
                z=-1.53887595621042e-1,
                vx=-2.17471785045538e-4,
                vy=-3.11361111025884e-3,
                vz=+3.58344705491441e-5)  # Neptune
    N = rebound.N

    def move_to_heliocentric():
        particles = rebound.particles

        for i in xrange(1, N):
            particles[i].x -= particles[0].x
            particles[i].y -= particles[0].y
            particles[i].z -= particles[0].z
            particles[i].vx -= particles[0].vx
            particles[i].vy -= particles[0].vy
            particles[i].vz -= particles[0].vz
        particles[0].x = 0.
        particles[0].y = 0.
        particles[0].z = 0.
        particles[0].vx = 0.
        particles[0].vy = 0.
        particles[0].vz = 0.

    def energy():
        if integrator == "wh":
            rebound.move_to_com()
        particles = rebound.particles
        E_kin = 0.
        E_pot = 0.
        for i in xrange(N):
            E_kin += 0.5 * particles[i].m * (
                particles[i].vx * particles[i].vx + particles[i].vy *
                particles[i].vy + particles[i].vz * particles[i].vz)
            for j in xrange(i + 1, N):
                dx = particles[i].x - particles[j].x
                dy = particles[i].y - particles[j].y
                dz = particles[i].z - particles[j].z
                r2 = dx * dx + dy * dy + dz * dz
                E_pot -= G * particles[i].m * particles[j].m / np.sqrt(r2)
        if integrator == "wh":
            move_to_heliocentric()
        return E_kin + E_pot

    rebound.move_to_com()
    ei = energy()

    es = 1e-20

    for s in xrange(1000):
        rebound.step()
        ef = energy()
        e = np.fabs((ei - ef) / ei)
        es = max(es, e)

    return es
Example #18
0
def simulation(par):
    integrator, mass = par
    rebound.reset()
    mass = pow(10.,mass)
    k = 0.01720209895    
    G = k*k
    rebound.G = G     
    rebound.dt = 0.
    rebound.integrator = integrator

    rebound.add(m=1.00000597682, x=-4.06428567034226e-3, y=-6.08813756435987e-3, z=-1.66162304225834e-6, vx=+6.69048890636161e-6, vy=-6.33922479583593e-6, vz=-3.13202145590767e-9)   # Sun
    rebound.add(m=mass,   x=+3.40546614227466e+0, y=+3.62978190075864e+0, z=+3.42386261766577e-2, vx=-5.59797969310664e-3, vy=+5.51815399480116e-3, vz=-2.66711392865591e-6)   # Jupiter
    rebound.add(m=mass,     x=+6.60801554403466e+0, y=+6.38084674585064e+0, z=-1.36145963724542e-1, vx=-4.17354020307064e-3, vy=+3.99723751748116e-3, vz=+1.67206320571441e-5)   # Saturn
    rebound.add(m=mass,     x=+1.11636331405597e+1, y=+1.60373479057256e+1, z=+3.61783279369958e-1, vx=-3.25884806151064e-3, vy=+2.06438412905916e-3, vz=-2.17699042180559e-5)   # Uranus
    rebound.add(m=mass,     x=-3.01777243405203e+1, y=+1.91155314998064e+0, z=-1.53887595621042e-1, vx=-2.17471785045538e-4, vy=-3.11361111025884e-3, vz=+3.58344705491441e-5)   # Neptune
    N = rebound.N

    def move_to_heliocentric():
        particles = rebound.particles
        
        for i in xrange(1,N):
            particles[i].x -= particles[0].x
            particles[i].y -= particles[0].y
            particles[i].z -= particles[0].z
            particles[i].vx -= particles[0].vx
            particles[i].vy -= particles[0].vy
            particles[i].vz -= particles[0].vz
        particles[0].x  = 0.
        particles[0].y  = 0. 
        particles[0].z  = 0. 
        particles[0].vx = 0. 
        particles[0].vy = 0. 
        particles[0].vz = 0. 


    def energy():
        if integrator=="wh":
            rebound.move_to_com()
        particles = rebound.particles
        E_kin = 0.
        E_pot = 0.
        for i in xrange(N):
            E_kin += 0.5*particles[i].m*(particles[i].vx*particles[i].vx + particles[i].vy*particles[i].vy + particles[i].vz*particles[i].vz)
            for j in xrange(i+1,N):
                dx = particles[i].x-particles[j].x
                dy = particles[i].y-particles[j].y
                dz = particles[i].z-particles[j].z
                r2 = dx*dx + dy*dy + dz*dz
                E_pot -= G*particles[i].m*particles[j].m/np.sqrt(r2)
        if integrator=="wh":
            move_to_heliocentric()
        return E_kin+E_pot

    rebound.move_to_com()
    ei = energy()

    es = 1e-20

    for s in xrange(1000):
        rebound.step()
        ef = energy()
        e = np.fabs((ei-ef)/ei)
        es = max(es,e)

    return es
Example #19
0
def simulation(par):
    import rebound
    integrator, dt, run = par
    rebound.reset()
    k = 0.01720209895    
    G = k*k
    rebound.G = G     
    rebound.dt = dt
    if integrator == "whfast-nocor":
        integrator = "whfast"
    else:
        rebound.integrator_whfast_corrector = 11
    rebound.integrator = integrator
    rebound.force_is_velocitydependent = 0

    rebound.add(m=1.00000597682, x=-4.06428567034226e-3, y=-6.08813756435987e-3, z=-1.66162304225834e-6, vx=+6.69048890636161e-6, vy=-6.33922479583593e-6, vz=-3.13202145590767e-9)   # Sun
    rebound.add(m=1./1407.355,   x=+3.40546614227466e+0, y=+3.62978190075864e+0, z=+3.42386261766577e-2, vx=-5.59797969310664e-3, vy=+5.51815399480116e-3, vz=-2.66711392865591e-6)   # Jupiter
    rebound.add(m=1./3501.6,     x=+6.60801554403466e+0, y=+6.38084674585064e+0, z=-1.36145963724542e-1, vx=-4.17354020307064e-3, vy=+3.99723751748116e-3, vz=+1.67206320571441e-5)   # Saturn
    rebound.add(m=1./22869.,     x=+1.11636331405597e+1, y=+1.60373479057256e+1, z=+3.61783279369958e-1, vx=-3.25884806151064e-3, vy=+2.06438412905916e-3, vz=-2.17699042180559e-5)   # Uranus
    rebound.add(m=1./19314.,     x=-3.01777243405203e+1, y=+1.91155314998064e+0, z=-1.53887595621042e-1, vx=-2.17471785045538e-4, vy=-3.11361111025884e-3, vz=+3.58344705491441e-5)   # Neptune
    N = rebound.N
    particles = rebound.particles
    np.random.seed(run)
    for i in xrange(N):
        particles[i].m *= 1.+1e-3*np.random.rand()
        particles[i].x *= 1.+1e-3*np.random.rand()
        particles[i].y *= 1.+1e-3*np.random.rand()
        particles[i].z *= 1.+1e-3*np.random.rand()
        particles[i].vx *= 1.+1e-3*np.random.rand()
        particles[i].vy *= 1.+1e-3*np.random.rand()
        particles[i].vz *= 1.+1e-3*np.random.rand()

    def move_to_heliocentric():
        particles[0].x  = 0.
        particles[0].y  = 0. 
        particles[0].z  = 0. 
        particles[0].vx = 0. 
        particles[0].vy = 0. 
        particles[0].vz = 0. 


    def energy():
        com_vx = 0.
        com_vy = 0.
        com_vz = 0.
        if integrator=="wh" or integrator=="mercury" or integrator[0:7]=="swifter":
            mtot = 0.
            for i in xrange(0,N):
                com_vx += particles[i].vx*particles[i].m 
                com_vy += particles[i].vy*particles[i].m 
                com_vz += particles[i].vz*particles[i].m 
                mtot += particles[i].m
            com_vx /= mtot
            com_vy /= mtot
            com_vz /= mtot
        E_kin = 0.
        E_pot = 0.
        for i in xrange(N):
            dvx = particles[i].vx - com_vx
            dvy = particles[i].vy - com_vy
            dvz = particles[i].vz - com_vz
            E_kin += 0.5*particles[i].m*(dvx*dvx + dvy*dvy + dvz*dvz)
            for j in xrange(i+1,N):
                dx = particles[i].x-particles[j].x
                dy = particles[i].y-particles[j].y
                dz = particles[i].z-particles[j].z
                r2 = dx*dx + dy*dy + dz*dz
                E_pot -= G*particles[i].m*particles[j].m/np.sqrt(r2)
        return E_kin+E_pot

    if integrator=="wh" or integrator=="mercury" or integrator[0:7]=="swifter":
        move_to_heliocentric()
    else:
        rebound.move_to_com()
    ei = energy()


    runtime = 0.
    rebound.integrate(tmax,exact_finish_time=0)
    ef = energy()
    e = np.fabs((ei-ef)/ei)+1.1e-16
    runtime += rebound.timing
    
    integrator, dt, run = par
    print integrator.ljust(13) + " %9.5fs"%(runtime) + "\t Error: %e"  %( e)
    return [runtime, e]