def test_orbmethods(): from galpy.orbit import Orbit from galpy.potential import MWPotential2014 # 8/17/2019: added explicit z=0.025, because that was the default at the # time of the galpy paper, but the default has been changed o = Orbit([0.8, 0.3, 0.75, 0., 0.2, 0.], zo=0.025) # setup R,vR,vT,z,vz,phi times = numpy.linspace(0., 10., 1001) # Output times o.integrate(times, MWPotential2014) # Integrate o.E() # Energy assert numpy.fabs(o.E() + 1.2547650648697966 ) < 10.**-5., 'Orbit method does not work as expected' o.L() # Angular momentum assert numpy.all( numpy.fabs(o.L() - numpy.array([[0., -0.16, 0.6]])) < 10.**-5. ), 'Orbit method does not work as expected' o.Jacobi(OmegaP=0.65) #Jacobi integral E-OmegaP Lz assert numpy.fabs(o.Jacobi(OmegaP=0.65) - numpy.array([-1.64476506]) ) < 10.**-5., 'Orbit method does not work as expected' o.ER(times[-1]), o.Ez(times[-1]) # Rad. and vert. E at end assert numpy.fabs(o.ER(times[-1]) + 1.27601734263047 ) < 10.**-5., 'Orbit method does not work as expected' assert numpy.fabs(o.Ez(times[-1]) - 0.021252201847851909 ) < 10.**-5., 'Orbit method does not work as expected' o.rperi(), o.rap(), o.zmax() # Peri-/apocenter r, max. |z| assert numpy.fabs(o.rperi() - 0.44231993168097 ) < 10.**-5., 'Orbit method does not work as expected' assert numpy.fabs(o.rap() - 0.87769030382105 ) < 10.**-5., 'Orbit method does not work as expected' assert numpy.fabs(o.zmax() - 0.077452357289016 ) < 10.**-5., 'Orbit method does not work as expected' o.e() # eccentricity (rap-rperi)/(rap+rperi) assert numpy.fabs(o.e() - 0.32982348199330563 ) < 10.**-5., 'Orbit method does not work as expected' o.R(2., ro=8.) # Cylindrical radius at time 2. in kpc assert numpy.fabs(o.R(2., ro=8.) - 3.5470772876920007 ) < 10.**-3., 'Orbit method does not work as expected' o.vR(5., vo=220.) # Cyl. rad. velocity at time 5. in km/s assert numpy.fabs(o.vR(5., vo=220.) - 45.202530965094553 ) < 10.**-3., 'Orbit method does not work as expected' o.ra(1.), o.dec(1.) # RA and Dec at t=1. (default settings) # 5/12/2016: test weakened, because improved galcen<->heliocen # transformation has changed these, but still close assert numpy.fabs(o.ra(1.) - numpy.array([288.19277]) ) < 10.**-1., 'Orbit method does not work as expected' assert numpy.fabs(o.dec(1.) - numpy.array([18.98069155]) ) < 10.**-1., 'Orbit method does not work as expected' o.jr(type='adiabatic'), o.jz() # R/z actions (ad. approx.) assert numpy.fabs(o.jr(type='adiabatic') - 0.05285302231137586 ) < 10.**-3., 'Orbit method does not work as expected' assert numpy.fabs(o.jz() - 0.006637988850751242 ) < 10.**-3., 'Orbit method does not work as expected' # Rad. period w/ Staeckel approximation w/ focal length 0.5, o.Tr(type='staeckel', delta=0.5, ro=8., vo=220.) # in Gyr assert numpy.fabs( o.Tr(type='staeckel', delta=0.5, ro=8., vo=220.) - 0.1039467864018446 ) < 10.**-3., 'Orbit method does not work as expected' o.plot(d1='R', d2='z') # Plot the orbit in (R,z) o.plot3d() # Plot the orbit in 3D, w/ default [x,y,z] return None
now_phi_omega = o.phi(ts)[-1] nowvr_om = o.vR(ts)[-1] nowvt_om = o.vT(ts)[-1] nowvz_om = o.vz(ts)[-1] #finding velocty components of omega cen now: now_arrayvr_omega = forward_omega_orbit.vR(-ts) now_arrayvt_omega = forward_omega_orbit.vT(-ts) now_arrayvz_omega = forward_omega_orbit.vz(-ts) now_vr_omega = forward_omega_orbit.vR(-ts)[-1] now_vt_omega = forward_omega_orbit.vT(-ts)[-1] now_vz_omega = forward_omega_orbit.vz(-ts)[-1] #finding energies of omega cen now: now_arraye_omega = forward_omega_orbit.E(-ts) now_arrayer_omega = forward_omega_orbit.ER(-ts) now_arrayez_omega = forward_omega_orbit.Ez(-ts) now_e_omega = now_arraye_omega[-1] now_er_omega = now_arrayer_omega[-1] now_ez_omega = now_arrayez_omega[-1] #print("current omega cen location according to code:", now_r_omega,now_vr_omega,now_vt_omega,now_z_omega,now_vz_omega,now_phi_omega) num_stars = 1000 vrom = o.vR() mu, sigma = (0, 100 / (np.sqrt(3))) sr = np.random.normal(mu, sigma, num_stars) vr_omega_array_vr = np.ones(num_stars) * (now_arrayvr_omega[0]) vt_omega_array_vt = np.ones(num_stars) * (now_arrayvt_omega[0]) vz_omega_array_vz = np.ones(num_stars) * (now_arrayvz_omega[0])
#star1 star1 = Orbit([(r_omega)*units.kpc, (vr_omega+10)*units.km/units.s, vt_omega*units.km/units.s, z_omega*units.kpc,vz_omega*units.km/units.s, phi_omega*units.deg], ro=8., vo=220., solarmotion='hogg') star1.integrate(-ts,MWPotential2014) #[R,vR,vT(,z,vz,phi)] #finding location of star 1 now: now_arrayz_star1 = star1.z(-ts) now_arrayR_star1 = star1.R(-ts) now_arrayphi_star1 = star1.phi(-ts) #finding velocty components of star 1 now: now_arrayvr_star1 = star1.vR(-ts) now_arrayvt_star1 = star1.vT(-ts) now_arrayvz_star1 = star1.vz(-ts) #finding energies of star 1 now: now_arraye_star1 = star1.E(-ts) now_arrayer_star1 = star1.ER(-ts) now_arrayez_star1 = star1.Ez(-ts) #compared with current orbit of omega cen arrayR_omega = forward_omega_orbit.R(-ts) arrayvr_omega = forward_omega_orbit.vR(-ts) arrayvt_omega = forward_omega_orbit.vT(-ts) arrayvz_omega = forward_omega_orbit.vz(-ts) arrayphi_omega = forward_omega_orbit.phi(-ts) arrayz_omega = forward_omega_orbit.z(-ts) rrr = arrayR_omega[-1] vrvr = arrayvr_omega[-1] vtvt = arrayvt_omega[-1] zzz = arrayz_omega[-1] vzvz = arrayvz_omega[-1] phiphi = arrayphi_omega[-1]