KEPLER /VELOCITY

        [BUNDLES\]KEPLER [/VSYSTEM Value]  /VELOCITY R Function(R)

      Use the functional form specified by Function(R) for the rotation velocity
    as  a  function  of  Radius.  The  default  is   the   Keplerian   law   KE-
    PLER_VMASS*sqrt(R/100).

      Note:  This  can allow to use the KEPLER command to handle rotation curves
    for galaxies, for example. However, the choice of radial units is not  obvi-
    ous  in  this  case.  It  can  be  made simple by setting the "distance" KE-
    PLER_DIST to 1 pc, so that the radii R are then just in arcsecond.