# galpy.df.streamdf.gaussApprox¶

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

NAME:

gaussApprox

PURPOSE:

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)

INPUT:

xy - phase-space point [X,Y,Z,vX,vY,vZ]; the distribution of the dimensions set to None is returned

interp= (object-wide interp default) if True, use the interpolated stream track

cindx= index of the closest point on the (interpolated) stream track if not given, determined from the dimensions given

lb= (False) 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

OUTPUT:

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

HISTORY:

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