galpy.df.evolveddiskdf.vmomentsurfacemass¶

evolveddiskdf.
vmomentsurfacemass
(R, n, m, t=0.0, nsigma=None, deg=False, epsrel=0.01, epsabs=1e05, phi=0.0, grid=None, gridpoints=101, returnGrid=False, hierarchgrid=False, nlevels=2, print_progress=False, integrate_method='dopr54_c', deriv=None)[source]¶ NAME:
vmomentsurfacemassPURPOSE:
calculate the an arbitrary moment of the velocity distribution at (R,phi) times the surfacmassINPUT:
R  radius at which to calculate the moment (in natural units)
phi= azimuth (rad unless deg=True)
n  vR^n
m  vT^m
t= time at which to evaluate the DF (can be a list or ndarray; if this is the case, list needs to be in descending order and equally spaced)
nsigma  number of sigma to integrate the velocities over (based on an estimate, so be generous, but not too generous)
deg= azimuth is in degree (default=False)
epsrel, epsabs  scipy.integrate keywords (the integration calculates the ratio of this vmoment to that of the initial DF)
grid= if set to True, build a grid and use that to evaluate integrals; if set to a gridobjects (such as returned by this procedure), use this grid; if this was created for a list of times, moments are calculated for each time
gridpoints= number of points to use for the grid in 1D (default=101)
returnGrid= if True, return the grid object (default=False)
hierarchgrid= if True, use a hierarchical grid (default=False)
nlevels= number of hierarchical levels for the hierarchical grid
print_progress= if True, print progress updates
integrate_method= orbit.integrate method argument
deriv= None, ‘R’, or ‘phi’: calculates derivative of the moment wrt R or phi onnly with grid options
OUTPUT:
<vR^n vT^m x surfacemass> at R,phi (no support for units)COMMENT:
gridbased calculation is the only one that is heavily tested (although the test suite also tests the direct calculation)HISTORY:
20110330  Written  Bovy (NYU)