ROTATIONCURVE(1)         TIPSY COMMANDS           ROTATIONCURVE(1)



NAME
     rotationcurve - calculate  the  circular  velocity  rotation
     curve

SYNOPSIS
     rotationcurve  box-number  center-box-number  binning   bin-
     number filename minimum_radius maximum_radius

ALIASES
     rotcur

DESCRIPTION
     rotationcurve is a command that  produces  a  file  of  name
     filename  that  contains the circular velocity as a function
     of radius gravitationally induced by the  particles  in  box
     box-number.

     The center of rotation is taken to be the center of mass  of
     the particles in box center-box-number. The binning argument
     refers to the distribution of the bins  where  the  circular
     velocity  is  evaluated,  either  linearly or log in radius.
     There are bin-number  bins  equally  distributed  in  either
     radius    or   log   radius   between   minimum_radius   and
     maximum_radius.

     The output file has the following four columns: the  radius,
     the  total  circular velocity, the circular velocity if only
     the dark matter were included, and the circular velocity  if
     only the baryonic matter (stars and gas) were included.  The
     circular velocity is calculated in a plane perpendicular  to
     the  angular  momentum axis of the gas particles in box box-
     number. The calculated velocity is the average of four  per-
     pendicular directions in this plane.

     If the boxes box-number or center-box-number are not  loaded
     an error is generated.  Boxes can be loaded using either the
     makebox, setbox, or setsphere commands.

OPTIONS
  Binning
     The possible choices for binning are:

          lin
             Make  bin-number  bins  spaced  equally  in   radius
             between minimum-radius and maximum_radius

          log
             Make bin-number bins spaced equally  in  log  radius
             between minimum-radius and maximum_radius

SEE ALSO
      makebox(1),  moments(1),  profile(1),  setbox(1),  setsphere(1)



KQ Release 2.0     Last change: 22 MARCH 1994                   1






 ROTATIONCURVE(1)         TIPSY COMMANDS           ROTATIONCURVE(1)



BUGS
     This command assumes  the  existence  of  gas  particles  to
     determine  the  plane  in which the rotation curve is calcu-
     lated.



















































KQ Release 2.0     Last change: 22 MARCH 1994                   2