def rforce(self,*args,**kwargs):
        """
        NAME:

           rforce

        PURPOSE:

           evaluate spherical radial force F_r  (R,z)

        INPUT:

           R - Cylindrical Galactocentric radius (can be Quantity)

           z - vertical height (can be Quantity)

           phi - azimuth (optional; can be Quantity)

           t - time (optional; can be Quantity)

           v - current velocity in cylindrical coordinates (optional, but required when including dissipative forces; can be a Quantity)

        OUTPUT:

           F_r (R,z,phi,t)

        HISTORY:

           2016-06-20 - Written - Bovy (UofT)

        """
        R,z= args
        r= numpy.sqrt(R**2.+z**2.)
        kwargs['use_physical']= False
        return self.Rforce(*args,**kwargs)*R/r+self.zforce(*args,**kwargs)*z/r
def rforce ( self , * args , ** kwargs ) : R , z = args r = numpy . sqrt ( R ** 2. + z ** 2. ) kwargs [ 'use_physical' ] = False return self . Rforce ( * args , ** kwargs ) * R / r + self . zforce ( * args , ** kwargs ) * z / r
NAME:

           rforce

        PURPOSE:

           evaluate spherical radial force F_r  (R,z)

        INPUT:

           R - Cylindrical Galactocentric radius (can be Quantity)

           z - vertical height (can be Quantity)

           phi - azimuth (optional; can be Quantity)

           t - time (optional; can be Quantity)

           v - current velocity in cylindrical coordinates (optional, but required when including dissipative forces; can be a Quantity)

        OUTPUT:

           F_r (R,z,phi,t)

        HISTORY:

           2016-06-20 - Written - Bovy (UofT)