galpy.df.evolveddiskdf.vertexdev¶
- evolveddiskdf.vertexdev(R, t=0.0, nsigma=None, deg=False, epsrel=0.01, epsabs=1e-05, phi=0.0, grid=None, gridpoints=101, returnGrid=False, sigmaR2=None, sigmaT2=None, sigmaRT=None, surfacemass=None, hierarchgrid=False, nlevels=2, integrate_method='dopr54_c')[source]¶
Calculate the vertex deviation of the velocity distribution at (R,phi)
- Parameters:
R (float) – radius at which to calculate the moment (can be Quantity)
t (float, optional) – 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) (can be Quantity), by default 0.0
nsigma (float, optional) – number of sigma to integrate the velocities over (based on an estimate, so be generous), by default None
deg (bool, optional) – azimuth is in degree (default=False); do not set this when giving phi as a Quantity, by default False
epsrel (float, optional) – scipy.integrate keywords (the integration calculates the ratio of this vmoment to that of the initial DF), by default 1.0e-02
epsabs (float, optional) – scipy.integrate keywords (the integration calculates the ratio of this vmoment to that of the initial DF), by default 1.0e-05
phi (float, optional) – azimuth (rad unless deg=True; can be Quantity), by default 0.0
grid (bool or evolveddiskdfGrid or evolveddiskdfHierarchicalGrid, optional) – if set to True, build a grid and use that to evaluate integrals; if set to a grid-objects (such as returned by this procedure), use this grid, by default None
gridpoints (int, optional) – number of points to use for the grid in 1D (default=101), by default 101
returnGrid (bool, optional) – if True, return the grid object (default=False), by default False
sigmaR2 (float, optional) – if set the vertex deviation is simply calculated using these, by default None
sigmaT2 (float, optional) – if set the vertex deviation is simply calculated using these, by default None
sigmaRT (float, optional) – if set the vertex deviation is simply calculated using these, by default None
surfacemass (None, optional) – Not used, by default None
hierarchgrid (bool, optional) – if True, use a hierarchical grid (default=False), by default False
nlevels (int, optional) – number of hierarchical levels for the hierarchical grid, by default 2
integrate_method (str, optional) – orbit.integrate method argument, by default “dopr54_c”
- Returns:
vertex deviation in rad or tuple of vertex deviation in rad and grid object
- Return type:
float or tuple
Notes
2011-03-31 - Written - Bovy (NYU)