Table of Contents

In addition to the potential value, the forces, it’s derivatives and the
poissonian density are calculated. The total table will hence contain: *x,
y, z, ax, ay, az, phi, phixx, phiyy, phizz, rho, dr, time*.

**potname=***name*- Generic name of the file which contains the description of
the potential. Some potentials require an addition data-file, see keyword
**potfile=**. [default: none]. **potpars=***parameters*- List of parameters for the
model. Will all be interpreted as double precision numbers. If less than
the required number of parameters are given, the remainder will be taken
from default settings in the potential routine. When too many are given,
the remaining are ignored. The first parameter, currently ignored, is reserved
for pattern speed, unless overridden with the
**omega=**keyword described below. [default: as defined by potential routine]. **potfile=***datafile*- Optional extra datafile which some potential descriptors use. Some files need a list of spline fitted points, others need an N-body snapshot etc. Most potentials will ignore this keyword though. [default: not set].
**x=***x-pos*- X-position(s)
where potential, forces and density are calculated. If more than one value
is given, it must be consistent with the number given in the other space
coordinates. See
*nemoinp(1,3)*for rules to provide multiple values. [default:**0.0**]. **y=***y-pos*- Y-position(s). See X. [default:
**0.0**]. **z=***z-pos*- Z-position(s). See X. [default:
**0.0**]. **t=***time*- If applicable, the time at which the potential is to be calculated.
[default:
**0.0**]. **dr=***value*- Differential in position which is used to numerically compute the force derivatives to compute the Laplacian. The poissonian density is then obtained after division by 4-pi. If no number is given, the densities are not computed, and only position, accelerations, potential and time are returned. Default: not used.
**omega=***pattern_speed*- Override value
for the pattern speed. Normally the pattern speed is defined by the first
argument in
**potpars=**, but this allows you to override. Forces and potentials are correctly displayed in the rotating frame of reference, but computing poissonian densities would not make sense without setting**omega=0**. Default: not used. **format=***fmt*- Format used in
*printf(3)*statement to print value. If no separator is provided, a space will be used. [Default:**%g**] **ndim=2|3**- Number of dimensions used in Poissonian density computation. Should be 2 or 3.
**double=t|f**- Force usage of Float or Double potentials. By default autodetected.
Old potentials (prior to 2001) are only available in double, which is the
default.

~src/orbit/potentialoriginal sources

13-Jul-87V1.0: Original createdPJT 8-Apr-88V2.0: added ’name’ parameter for hackforcePJT 5-May-88V2.1: small mods, renamed keywordsPJT 9-feb-90V3.0: added time dependant options, renamed keywordsPJT 26-jun-90V3.1: can give whole array of input positionsPJT 15-oct-93V5.1: new method(s) of getting pattern speedPJT 17-feb-94V5.2: added ndim=PJT 18-sep-01V4.0: handle both _float and _double potentialsPJT