def test_force_in_pcMyr2():
#Test the scaling, as a 1st derivative of the potential, should scale as velocity^2/position
vofid, rofid = 200., 8.
assert numpy.fabs(4. * bovy_conversion.force_in_pcMyr2(vofid, rofid) /
bovy_conversion.force_in_pcMyr2(2. * vofid, rofid) - 1.
) < 10.**-10., 'force_in_pcMyr2 did not work as expected'
assert numpy.fabs(.5 * bovy_conversion.force_in_pcMyr2(vofid, rofid) /
bovy_conversion.force_in_pcMyr2(vofid, 2 * rofid) - 1.
) < 10.**-10., 'force_in_pcMyr2 did not work as expected'
return None
def test_units():
import galpy.util.bovy_conversion as conversion
print(conversion.force_in_pcMyr2(220.,8.))#pc/Myr^2
assert numpy.fabs(conversion.force_in_pcMyr2(220.,8.)-6.32793804994) < 10.**-4., 'unit conversion has changed'
print(conversion.dens_in_msolpc3(220.,8.))#Msolar/pc^3
assert numpy.fabs(conversion.dens_in_msolpc3(220.,8.)-0.175790330079) < 10.**-4., 'unit conversion has changed'
print(conversion.surfdens_in_msolpc2(220.,8.))#Msolar/pc^2
assert numpy.fabs(conversion.surfdens_in_msolpc2(220.,8.)-1406.32264063) < 10.**-4., 'unit conversion has changed'
print(conversion.mass_in_1010msol(220.,8.))#10^10 Msolar
assert numpy.fabs(conversion.mass_in_1010msol(220.,8.)-9.00046490005) < 10.**-4., 'unit conversion has changed'
print(conversion.freq_in_Gyr(220.,8.))#1/Gyr
assert numpy.fabs(conversion.freq_in_Gyr(220.,8.)-28.1245845523) < 10.**-4., 'unit conversion has changed'
print(conversion.time_in_Gyr(220.,8.))#Gyr
assert numpy.fabs(conversion.time_in_Gyr(220.,8.)-0.0355560807712) < 10.**-4., 'unit conversion has changed'
return None
def test_units():
import galpy.util.bovy_conversion as conversion
print(conversion.force_in_pcMyr2(220.,8.))#pc/Myr^2
assert numpy.fabs(conversion.force_in_pcMyr2(220.,8.)-6.32793804994) < 10.**-4., 'unit conversion has changed'
print(conversion.dens_in_msolpc3(220.,8.))#Msolar/pc^3
assert numpy.fabs((conversion.dens_in_msolpc3(220.,8.)-0.175790330079)/0.175790330079) < 5.*10.**-5., 'unit conversion has changed'
print(conversion.surfdens_in_msolpc2(220.,8.))#Msolar/pc^2
assert numpy.fabs((conversion.surfdens_in_msolpc2(220.,8.)-1406.32264063)/1406.32264063) < 5.*10.**-5., 'unit conversion has changed'
print(conversion.mass_in_1010msol(220.,8.))#10^10 Msolar
assert numpy.fabs((conversion.mass_in_1010msol(220.,8.)-9.00046490005)/9.00046490005) < 5.*10.**-5., 'unit conversion has changed'
print(conversion.freq_in_Gyr(220.,8.))#1/Gyr
assert numpy.fabs(conversion.freq_in_Gyr(220.,8.)-28.1245845523) < 10.**-4., 'unit conversion has changed'
print(conversion.time_in_Gyr(220.,8.))#Gyr
assert numpy.fabs(conversion.time_in_Gyr(220.,8.)-0.0355560807712) < 10.**-4., 'unit conversion has changed'
return None
def __init__(self,K=1.15,F=0.03,D=1.8,amp=1.,ro=None,vo=None):
"""
NAME:
__init__
PURPOSE:
Initialize a KGPotential
INPUT:
K= K parameter (= :math:`2\\pi \\Sigma_{\\mathrm{disk}}`; specify either as surface density or directly as force [i.e., including :math:`2\\pi G`]; can be Quantity)
F= F parameter (= :math:`4\\pi\\rho_{\\mathrm{halo}}`; specify either as density or directly as second potential derivative [i.e., including :math:`4\\pi G`]; can be Quantity)
D= D parameter (natural units or Quantity length units)
amp - an overall amplitude
OUTPUT:
instance
HISTORY:
2010-07-12 - Written - Bovy (NYU)
"""
linearPotential.__init__(self,amp=amp,ro=ro,vo=vo)
if _APY_LOADED and isinstance(D,units.Quantity):
D= D.to(units.kpc).value/self._ro
if _APY_LOADED and isinstance(K,units.Quantity):
try:
K= K.to(units.pc/units.Myr**2).value\
/bovy_conversion.force_in_pcMyr2(self._vo,self._ro)
except units.UnitConversionError: pass
if _APY_LOADED and isinstance(K,units.Quantity):
try:
K= K.to(units.Msun/units.pc**2).value\
/bovy_conversion.force_in_2piGmsolpc2(self._vo,self._ro)
except units.UnitConversionError:
raise units.UnitConversionError("Units for K not understood; should be force or surface density")
if _APY_LOADED and isinstance(F,units.Quantity):
try:
F= F.to(units.Msun/units.pc**3).value\
/bovy_conversion.dens_in_msolpc3(self._vo,self._ro)*4.*sc.pi
except units.UnitConversionError: pass
if _APY_LOADED and isinstance(F,units.Quantity):
try:
F= F.to(units.km**2/units.s**2/units.kpc**2).value\
*ro**2/vo**2
except units.UnitConversionError:
raise units.UnitConversionError("Units for F not understood; should be density")
self._K= K
self._F= F
self._D= D
self._D2= self._D**2.
self.hasC= True
def rv(x, y, z):
conv = bovy_conversion.force_in_pcMyr2(220., 8) * u.pc / (
u.Myr**2) ##Unit conversion
x *= u.kpc
y *= u.kpc
z *= u.kpc
##Sun's location
sx = 8 * u.kpc
sy = 0 * u.kpc
sz = 4 * u.kpc
sun_ar = evaluateRforces(poten, sx, sz, phi=0 * u.deg) * conv
sun_az = evaluatezforces(poten, sx, sz, phi=0 * u.deg) * conv
sun_acc = Vector(sun_ar, 0 * conv, sun_az)
star_ar = evaluateRforces(poten, np.sqrt(x**2 + y**2), z,
phi=0 * u.deg) * conv
star_az = evaluatezforces(poten, np.sqrt(x**2 + y**2), z,
phi=0 * u.deg) * conv
star_acc = Vector(star_ar, 0 * conv, star_az)
heliocentric_acc = Vector(star_acc.x - sun_acc.x, star_acc.y - sun_acc.y,
star_acc.z - sun_acc.z)
r = Vector(sx - x, sy - y, sz - z)
acc = r.project(heliocentric_acc)
delta_v = (acc.mag * 10 * u.yr).to(u.cm / u.s)
return delta_v, r
def __init__(self, K=1.15, F=0.03, D=1.8, amp=1., ro=None, vo=None):
"""
NAME:
__init__
PURPOSE:
Initialize a KGPotential
INPUT:
K= K parameter (= :math:`2\\pi \\Sigma_{\\mathrm{disk}}`; specify either as surface density or directly as force [i.e., including :math:`2\\pi G`]; can be Quantity)
F= F parameter (= :math:`4\\pi\\rho_{\\mathrm{halo}}`; specify either as density or directly as second potential derivative [i.e., including :math:`4\\pi G`]; can be Quantity)
D= D parameter (natural units or Quantity length units)
amp - an overall amplitude
OUTPUT:
instance
HISTORY:
2010-07-12 - Written - Bovy (NYU)
"""
linearPotential.__init__(self, amp=amp, ro=ro, vo=vo)
if _APY_LOADED and isinstance(D, units.Quantity):
D = D.to(units.kpc).value / self._ro
if _APY_LOADED and isinstance(K, units.Quantity):
try:
K= K.to(units.pc/units.Myr**2).value\
/bovy_conversion.force_in_pcMyr2(self._vo,self._ro)
except units.UnitConversionError:
pass
if _APY_LOADED and isinstance(K, units.Quantity):
try:
K= K.to(units.Msun/units.pc**2).value\
/bovy_conversion.force_in_2piGmsolpc2(self._vo,self._ro)
except units.UnitConversionError:
raise units.UnitConversionError(
"Units for K not understood; should be force or surface density"
)
if _APY_LOADED and isinstance(F, units.Quantity):
try:
F= F.to(units.Msun/units.pc**3).value\
/bovy_conversion.dens_in_msolpc3(self._vo,self._ro)*4.*sc.pi
except units.UnitConversionError:
pass
if _APY_LOADED and isinstance(F, units.Quantity):
try:
F= F.to(units.km**2/units.s**2/units.kpc**2).value\
*ro**2/vo**2
except units.UnitConversionError:
raise units.UnitConversionError(
"Units for F not understood; should be density")
self._K = K
self._F = F
self._D = D
self._D2 = self._D**2.
def test_force_in_pcMyr2():
#Test the scaling, as a 1st derivative of the potential, should scale as velocity^2/position
vofid, rofid= 200., 8.
assert numpy.fabs(4.*bovy_conversion.force_in_pcMyr2(vofid,rofid)/bovy_conversion.force_in_pcMyr2(2.*vofid,rofid)-1.) < 10.**-10., 'force_in_pcMyr2 did not work as expected'
assert numpy.fabs(.5*bovy_conversion.force_in_pcMyr2(vofid,rofid)/bovy_conversion.force_in_pcMyr2(vofid,2*rofid)-1.) < 10.**-10., 'force_in_pcMyr2 did not work as expected'
return None
