streamdf.gaussApprox(xy, **kwargs)[source]

Return the mean and variance of a Gaussian approximation to the stream DF at a given phase-space point in Galactocentric rectangular coordinates (distribution is over missing directions)

  • xy (numpy.ndarray) – Phase-space point [X,Y,Z,vX,vY,vZ]; the distribution of the dimensions set to None is returned.

  • interp (bool, optional) – If True, use the interpolated stream track. Default is True.

  • cindx (int, optional) – Index of the closest point on the (interpolated) stream track if not given, determined from the dimensions given.

  • lb (bool, optional) – If True, xy contains [l,b,D,vlos,pmll,pmbb] in [deg,deg,kpc,km/s,mas/yr,mas/yr] and the Gaussian approximation in these coordinates is returned. Default is False.


(mean,variance) of the approximate Gaussian DF for the missing directions in xy.

Return type:



  • 2013-12-12 - Written - Bovy (IAS).