Exemplo n.º 1
0
def test_impulse_deltav_general_orbit_zeroforce():
    from galpy.df import impulse_deltav_plummer_curvedstream, \
        impulse_deltav_general_orbitintegration
    from galpy.potential import PlummerPotential
    tol= -6.
    rcurv=10.
    vp=220.
    x0 = numpy.array([rcurv,0.,0.])
    v0 = numpy.array([0.,vp,0.])
    w = numpy.array([1.,numpy.pi/2.,0.])
    plummer_kick= impulse_deltav_plummer_curvedstream(\
        v0,x0,3.,w,x0,v0,1.5,4.)
    pp= PlummerPotential(amp=1.5,b=4.)
    vang=vp/rcurv
    angrange=numpy.pi
    maxt=5.*angrange/vang
    galpot = constantPotential()
    orbit_kick= impulse_deltav_general_orbitintegration(\
        v0,x0,3.,w,x0,v0,pp,maxt,galpot)
    assert numpy.all(numpy.fabs(orbit_kick-plummer_kick) < 10.**tol), \
        'general kick with acceleration calculation does not agree with Plummer calculation for a Plummer potential, for straight'
    # Same for a bunch of positions
    tol= -5.
    pp= PlummerPotential(amp=numpy.pi,b=numpy.exp(1.))
    theta = numpy.linspace(-numpy.pi/4.,numpy.pi/4.,100)
    xc,yc = rcurv*numpy.cos(theta),rcurv*numpy.sin(theta)
    Xc = numpy.zeros((100,3))
    Xc[:,0]=xc
    Xc[:,1]=yc
    vx,vy = -vp*numpy.sin(theta),vp*numpy.cos(theta)
    V = numpy.zeros((100,3))
    V[:,0]=vx
    V[:,1]=vy
    plummer_kick= impulse_deltav_plummer_curvedstream(\
        V,Xc,3.,w,x0,v0,numpy.pi,numpy.exp(1.))
    orbit_kick= impulse_deltav_general_orbitintegration(\
        V,Xc,3.,w,x0,v0,pp,
        maxt,
        galpot)
    assert numpy.all(numpy.fabs(orbit_kick-plummer_kick) < 10.**tol), \
            'general kick calculation does not agree with Plummer calculation for a Plummer potential, for curved stream'
    return None
Exemplo n.º 2
0
def test_impulse_deltav_general_orbit_zeroforce():
    from galpy.df import impulse_deltav_plummer_curvedstream, \
        impulse_deltav_general_orbitintegration
    from galpy.potential import PlummerPotential
    tol= -6.
    rcurv=10.
    vp=220.
    x0 = numpy.array([rcurv,0.,0.])
    v0 = numpy.array([0.,vp,0.])
    w = numpy.array([1.,numpy.pi/2.,0.])
    plummer_kick= impulse_deltav_plummer_curvedstream(\
        v0,x0,3.,w,x0,v0,1.5,4.)
    pp= PlummerPotential(amp=1.5,b=4.)
    vang=vp/rcurv
    angrange=numpy.pi
    maxt=5.*angrange/vang
    galpot = constantPotential()
    orbit_kick= impulse_deltav_general_orbitintegration(\
        v0,x0,3.,w,x0,v0,pp,maxt,galpot)
    assert numpy.all(numpy.fabs(orbit_kick-plummer_kick) < 10.**tol), \
        'general kick with acceleration calculation does not agree with Plummer calculation for a Plummer potential, for straight'
    # Same for a bunch of positions
    tol= -5.
    pp= PlummerPotential(amp=numpy.pi,b=numpy.exp(1.))
    theta = numpy.linspace(-numpy.pi/4.,numpy.pi/4.,100)
    xc,yc = rcurv*numpy.cos(theta),rcurv*numpy.sin(theta)
    Xc = numpy.zeros((100,3))
    Xc[:,0]=xc
    Xc[:,1]=yc
    vx,vy = -vp*numpy.sin(theta),vp*numpy.cos(theta)
    V = numpy.zeros((100,3))
    V[:,0]=vx
    V[:,1]=vy
    plummer_kick= impulse_deltav_plummer_curvedstream(\
        V,Xc,3.,w,x0,v0,numpy.pi,numpy.exp(1.))
    orbit_kick= impulse_deltav_general_orbitintegration(\
        V,Xc,3.,w,x0,v0,pp,
        maxt,
        galpot)
    assert numpy.all(numpy.fabs(orbit_kick-plummer_kick) < 10.**tol), \
            'general kick calculation does not agree with Plummer calculation for a Plummer potential, for curved stream'
    return None
Exemplo n.º 3
0
def test_impulse_deltav_general_fullintegration_fastencounter():
    from galpy.df import impulse_deltav_general_orbitintegration, \
        impulse_deltav_general_fullplummerintegration
    from galpy.potential import PlummerPotential, LogarithmicHaloPotential
    tol= -2.
    GM=1.5
    rs=4.
    x0 = numpy.array([1.5,0.,0.])
    v0 = numpy.array([0.,1.,0.]) #circular orbit
    w = numpy.array([0.,0.,100.]) # very fast compared to v=1
    lp= LogarithmicHaloPotential(normalize=1.)
    pp= PlummerPotential(amp=GM,b=rs)
    orbit_kick= impulse_deltav_general_orbitintegration(\
        v0,x0,3.,w,x0,v0,pp,5.*numpy.pi,lp)
    full_kick= impulse_deltav_general_fullplummerintegration(\
        v0,x0,3.,w,x0,v0,lp,GM,rs,tmaxfac=10.,N=1000)
    # Kick should be in the X direction
    assert numpy.fabs((orbit_kick-full_kick)/full_kick)[0,0] < 10.**tol, \
        'Acceleration kick does not agree with full-orbit-integration kick for fast encounter'
    assert numpy.all(numpy.fabs((orbit_kick-full_kick))[0,1:] < 10.**tol), \
        'Acceleration kick does not agree with full-orbit-integration kick for fast encounter'
    return None
Exemplo n.º 4
0
def test_impulse_deltav_general_fullintegration_fastencounter():
    from galpy.df import impulse_deltav_general_orbitintegration, \
        impulse_deltav_general_fullplummerintegration
    from galpy.potential import PlummerPotential, LogarithmicHaloPotential
    tol= -2.
    GM=1.5
    rs=4.
    x0 = numpy.array([1.5,0.,0.])
    v0 = numpy.array([0.,1.,0.]) #circular orbit
    w = numpy.array([0.,0.,100.]) # very fast compared to v=1
    lp= LogarithmicHaloPotential(normalize=1.)
    pp= PlummerPotential(amp=GM,b=rs)
    orbit_kick= impulse_deltav_general_orbitintegration(\
        v0,x0,3.,w,x0,v0,pp,5.*numpy.pi,lp)
    full_kick= impulse_deltav_general_fullplummerintegration(\
        v0,x0,3.,w,x0,v0,lp,GM,rs,tmaxfac=10.,N=1000)
    # Kick should be in the X direction
    assert numpy.fabs((orbit_kick-full_kick)/full_kick)[0,0] < 10.**tol, \
        'Acceleration kick does not agree with full-orbit-integration kick for fast encounter'
    assert numpy.all(numpy.fabs((orbit_kick-full_kick))[0,1:] < 10.**tol), \
        'Acceleration kick does not agree with full-orbit-integration kick for fast encounter'
    return None