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name

addgravity - adds gravity to a snapshot; using falcON (public version)

synopsis

addgravity [parameter=value]

requirement

requires NEMO version 3.0.13 or higher, see http://www.astro.umd.edu/nemo.

description

addgravity uses Walter Dehnen’s force algorithm of complexity O(N) (falcON), to add the gravitational potential and accelerations to NEMO snapshots.

parameters

in=file
Input snapshots are read from file, which must be in NEMO snapshot format. If file=-, input is expected from stdin, useful for piping data from another program. Default: required
out=file
Snapshots are written in NEMO snapshot format to file with same body data as the input plus acceleration and potential. Default: required.
times=time range(s)
Range(s) of simulation times, for which snapshots shall be processed. Default: all.
eps=val
The (globally constant) softening length is set to val. For details, see documentation in the user guide. Default: 0.05.
kernel=num
The softening kernel is taken to be the Pnum kernel (see the documentation in the user guide). Default: 1.
theta=val
The tolerance parameter for falcON is set to val. It is recommended to stick to the default or smaller value, but see the discussion in the falcON user guide Default: 0.6.
Ncrit=num
In building the tree, a cell containg num bodies or less is not splitted. Default: 6.

see also

gyrfalcON(1falcON) , getgravity(1falcON)


Dehnen, W., 2000, ApJ, 536, L39
Dehnen, W., 2002, JCP, 179, 27

files


falcON/doc/user_guide.pdf                         User Guide for falcON

author


Walter Dehnen                              walter.dehnen@astro.le.ac.uk
update history of this man page
18-May-2004    first version of manual  WD


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