Table of Contents

In case
a true rotation curve is requested (**mode=velocity**) the table contains *r,
v, v1, v2, ...*, whereas the Lindblad option with **mode=omega** tabulates *r, v,
omega, kappa, omega+kappa/2, omega-kappa/2*.

**name1=***potname*- Name of first potential, in standard
*potential(5EMO)*format. No default allowed. **pars1=***potpars*- Parameters for first potential. Defaults as defined by the potential itself.
**file1=***potfile*- Optional file for first potential. Defaults as defined by the potential itself.
**name2=**- See name1= for second potential
**pars2=**- See pars1=
**file2=**- See file1=
**name3=**- See name1= for third potential
**pars3=**- See pars1=
**file3=**- See file1=
**name4=**- See name1= for fourth potential
**pars4=**- See pars1=
**file4=**- See file1=

NOTE that because of the specific code implementation, you cannot re-use the same potential, since they share their static code data. **radii=***r1,r2,...*- Radii where to compute the rotation curve. [default:
**0:2:0.1**]. **axis=x|y|z**- Choice
of axis to compute rotation curve along. The rotation curve is defined from
circular orbits balancing the local gravitational force. [default:
**x**]. **mode=***option*- Mode can be
**velocity**or**omega**, the former selecting the true rotation curve, the latter a Lindblad diagram. In a Lindblad diagram only the total curve is given, not the individual components. If a finite pattern speed is given, it also computes the lindblad resonances, but make sure the OLR is included, else the program will abort. [default:**velocity**]. **n=**- For angular velocity
diagrams (
**mode=omega**) this gives the Lindblad resonance to be computed. By default the classical**n=2**is used, from which the ILR and OLR can be derived. For**n=4**the two UHR can be determined etc. [Default:**2**] **r0l=***r0,l,radii*- Solar radius, galactic longitude and a list of radii (distances along
the line of sight) to calculate radial velocity for.
*Experimental, only in*mode**lv** **dr=**- If given, the forces along the selected cardinal direction
(see
**dir=**) will be computed via a first order numerical derivative from two points **plot=t|f**- Select viewing in form of a plot. [Default:
**t**] **tab=t|f**- Select viewing in form of a table. [Default:
**f**] **format=***printf(3)*style format specification for each of the columns in tabular output. [Default:**%g**]**xrange=***xmin,xmax|xmin*- Range in plot for X-axis, always radius. Two (min and max), one (min) or zero (autoscaling) values can be given. [default: autoscaling]
**yrange=***ymin,ymax|ymin*- Range in plot for Y-axis, either velocity
or omega. See also
**xrange=**. [default: autoscaling] **headline=***plotlabel_text*- Any optional text, plotted at the top of the plot for identification purposes.
The default is a list of
*nameX(parsX)**...*. **in=***table_file*- If supplied, it should be a table (a file) consisting of velocities (colum 2) vs. radius (column 1) to be checking with the composite model supplied earlier. Some kind of statistics will be calculated from which the goodness of fit can be derived. [default: not used].
**cols=***rcol,vcol,drcol,dvcol*- The columns must be provided
here in which columns the radius, velocity, error in radius and error in
velocity can be found. The error columns are optional, and if provided error
bars will be plotted on top of the data. A 0 can be used if an column is
not present in the data, although radius and velocity must always be present.
[Default:
**1,2**].

galfit: https://users.obs.carnegiescience.edu/peng/work/galfit/galfit.html galphot: http://www.astro-wise.org/portal/howtos/man_howto_galphot/man_howto_galphot.shtml

Although not really a bug, but a limitation, this program
assumes symmetric potentials, and that circular orbits exist in the selected
plane. For non-axisymmetric potentials the obtained rotation curve is bogus,
and one has to resort to a periodic orbit searching program such as *perorb(1NEMO)*
.
You can also try and average the results along the X and Y axes, and average.

Rotating potentials are not implemented, except for the search for Lindblad
resonances in **mode=omega**.

Potentials (name1,2,....) cannot be re-used. Since *loadobj(3NEMO)*
is used to load the potentials, their static code data is shared. One possible

solution would be to make a physical copy of the .so file from $NEMOOBJ/potential

in the local directory with different names

~/src/orbit/potential rotcurves.c

xx-oct-90 V1.0 derived from potlist PJT 28-oct-90 V1.1 spline fit -> lindblad option PJT 8-nov-90 V1.2 in= table implemented PJT 16-nov-90V1.3 cols= to select optional error columsPJT 12-nov-93V1.4 added n=PJT 8-apr-97V1.6 search for lindblad resonances if omega>0PJT 7-jul-02V1.7 added format=PJT mar-2021V1.2 added dr= to allow for forceless potentialsPJT