def omegac(Pot,R):
"""
NAME:
omegac
PURPOSE:
calculate the circular angular speed velocity at R in potential Pot
INPUT:
Pot - Potential instance or list of such instances
R - Galactocentric radius
OUTPUT:
circular angular speed
HISTORY:
2011-10-09 - Written - Bovy (IAS)
"""
from planarPotential import evaluateplanarRforces
try:
return nu.sqrt(-evaluateplanarRforces(R,Pot)/R)
except TypeError:
from planarPotential import RZToplanarPotential
Pot= RZToplanarPotential(Pot)
return nu.sqrt(-evaluateplanarRforces(R,Pot)/R)
def dvcircdR(Pot,R):
"""
NAME:
dvcircdR
PURPOSE:
calculate the derivative of the circular velocity wrt R at R in potential Pot
INPUT:
Pot - Potential instance or list of such instances
R - Galactocentric radius
OUTPUT:
derivative of the circular rotation velocity wrt R
HISTORY:
2013-01-08 - Written - Bovy (IAS)
"""
from planarPotential import evaluateplanarRforces
from planarPotential import evaluateplanarR2derivs
tvc= vcirc(Pot,R)
try:
return 0.5*(-evaluateplanarRforces(R,Pot)+R*evaluateplanarR2derivs(R,Pot))/tvc
except TypeError:
from planarPotential import RZToplanarPotential
Pot= RZToplanarPotential(Pot)
return 0.5*(-evaluateplanarRforces(R,Pot)+R*evaluateplanarR2derivs(R,Pot))/tvc
def vcirc(Pot,R):
"""
NAME:
vcirc
PURPOSE:
calculate the circular velocity at R in potential Pot
INPUT:
Pot - Potential instance or list of such instances
R - Galactocentric radius
OUTPUT:
circular rotation velocity
HISTORY:
2011-10-09 - Written - Bovy (IAS)
"""
from planarPotential import evaluateplanarRforces
from Potential import PotentialError
try:
return nu.sqrt(-R*evaluateplanarRforces(R,Pot))
except PotentialError:
from planarPotential import RZToplanarPotential
Pot= RZToplanarPotential(Pot)
return nu.sqrt(-R*evaluateplanarRforces(R,Pot))
def calcRotcurve(Pot,Rs):
"""
NAME:
calcRotcurve
PURPOSE:
calculate the rotation curve for this potential (in the z=0 plane for
non-spherical potentials)
INPUT:
Pot - Potential or list of Potential instances
Rs - (array of) radius(i)
OUTPUT:
array of vc
HISTORY:
2011-04-13 - Written - Bovy (NYU)
"""
isList= isinstance(Pot,list)
isNonAxi= ((isList and Pot[0].isNonAxi) or (not isList and Pot.isNonAxi))
if isNonAxi:
raise AttributeError("Rotation curve plotting for non-axisymmetric potentials is not currently supported")
try:
grid= len(Rs)
except TypeError:
grid=1
Rs= nu.array([Rs])
rotcurve= nu.zeros(grid)
from planarPotential import evaluateplanarRforces
for ii in range(grid):
try:
rotcurve[ii]= nu.sqrt(Rs[ii]*-evaluateplanarRforces(Rs[ii],Pot))
except TypeError:
from planarPotential import RZToplanarPotential
Pot= RZToplanarPotential(Pot)
rotcurve[ii]= nu.sqrt(Rs[ii]*-evaluateplanarRforces(Rs[ii],Pot))
return rotcurve
def epifreq(Pot,R):
"""
NAME:
epifreq
PURPOSE:
calculate the epicycle frequency at R in potential Pot
INPUT:
Pot - Potential instance or list of such instances
R - Galactocentric radius
OUTPUT:
epicycle frequency
HISTORY:
2011-10-09 - Written - Bovy (IAS)
"""
from planarPotential import evaluateplanarRforces, evaluateplanarR2derivs
try:
return nu.sqrt(evaluateplanarR2derivs(R,Pot)-3./R*evaluateplanarRforces(R,Pot))
except TypeError:
from planarPotential import RZToplanarPotential
Pot= RZToplanarPotential(Pot)
return nu.sqrt(evaluateplanarR2derivs(R,Pot)-3./R*evaluateplanarRforces(R,Pot))
def omegac(Pot, R):
"""
NAME:
omegac
PURPOSE:
calculate the circular angular speed velocity at R in potential Pot
INPUT:
Pot - Potential instance or list of such instances
R - Galactocentric radius
OUTPUT:
circular angular speed
HISTORY:
2011-10-09 - Written - Bovy (IAS)
"""
from planarPotential import evaluateplanarRforces
try:
return nu.sqrt(-evaluateplanarRforces(R, Pot) / R)
except TypeError:
from planarPotential import RZToplanarPotential
Pot = RZToplanarPotential(Pot)
return nu.sqrt(-evaluateplanarRforces(R, Pot) / R)
def calcRotcurve(Pot, Rs):
"""
NAME:
calcRotcurve
PURPOSE:
calculate the rotation curve for this potential (in the z=0 plane for
non-spherical potentials)
INPUT:
Pot - Potential or list of Potential instances
Rs - (array of) radius(i)
OUTPUT:
array of vc
HISTORY:
2011-04-13 - Written - Bovy (NYU)
"""
isList = isinstance(Pot, list)
isNonAxi = ((isList and Pot[0].isNonAxi) or (not isList and Pot.isNonAxi))
if isNonAxi:
raise AttributeError(
"Rotation curve plotting for non-axisymmetric potentials is not currently supported"
)
try:
grid = len(Rs)
except TypeError:
grid = 1
Rs = nu.array([Rs])
rotcurve = nu.zeros(grid)
from planarPotential import evaluateplanarRforces
for ii in range(grid):
try:
rotcurve[ii] = nu.sqrt(Rs[ii] *
-evaluateplanarRforces(Rs[ii], Pot))
except TypeError:
from planarPotential import RZToplanarPotential
Pot = RZToplanarPotential(Pot)
rotcurve[ii] = nu.sqrt(Rs[ii] *
-evaluateplanarRforces(Rs[ii], Pot))
return rotcurve
def epifreq(Pot,R):
"""
NAME:
epifreq
PURPOSE:
calculate the epicycle frequency at R in the potential Pot
INPUT:
Pot - Potential instance or list thereof
R - Galactocentric radius
OUTPUT:
epicycle frequency
HISTORY:
2012-07-25 - Written - Bovy (IAS)
"""
from galpy.potential_src.planarPotential import planarPotential
if isinstance(Pot,(Potential,planarPotential)):
return Pot.epifreq(R)
from planarPotential import evaluateplanarRforces, evaluateplanarR2derivs
from Potential import PotentialError
try:
return nu.sqrt(evaluateplanarR2derivs(R,Pot)-3./R*evaluateplanarRforces(R,Pot))
except PotentialError:
from planarPotential import RZToplanarPotential
Pot= RZToplanarPotential(Pot)
return nu.sqrt(evaluateplanarR2derivs(R,Pot)-3./R*evaluateplanarRforces(R,Pot))
def epifreq(Pot, R):
"""
NAME:
epifreq
PURPOSE:
calculate the epicycle frequency at R in potential Pot
INPUT:
Pot - Potential instance or list of such instances
R - Galactocentric radius
OUTPUT:
epicycle frequency
HISTORY:
2011-10-09 - Written - Bovy (IAS)
"""
from planarPotential import evaluateplanarRforces, evaluateplanarR2derivs
try:
return nu.sqrt(
evaluateplanarR2derivs(R, Pot) -
3. / R * evaluateplanarRforces(R, Pot))
except TypeError:
from planarPotential import RZToplanarPotential
Pot = RZToplanarPotential(Pot)
return nu.sqrt(
evaluateplanarR2derivs(R, Pot) -
3. / R * evaluateplanarRforces(R, Pot))
