Command line options
SWIFT requires a number of runtime options to run and get any sensible output.
For instance, just running the swift binary will not use any SPH or gravity;
the particles will just sit still!
Below is a list of the command line options and when they should be used. The same list
can be found by typing ./swift -h:
-h, --help show this help message and exit
Simulation options:
-b, --feedback Run with stars feedback.
-c, --cosmology Run with cosmological time integration.
--temperature Run with temperature calculation.
-C, --cooling Run with cooling (also switches on --temperature).
-D, --drift-all Always drift all particles even the ones
far from active particles. This emulates
Gadget-[23] and GIZMO's default behaviours.
-F, --star-formation Run with star formation.
-g, --external-gravity Run with an external gravitational potential.
-G, --self-gravity Run with self-gravity.
-M, --multipole-reconstruction Reconstruct the multipoles every time-step.
-s, --hydro Run with hydrodynamics.
-S, --stars Run with stars.
-B, --black-holes Run with black holes.
-u, --fof Run Friends-of-Friends algorithm to
perform black hole seeding.
-x, --velociraptor Run with structure finding.
--limiter Run with time-step limiter.
--sync Run with time-step synchronization
of particles hit by feedback events.
--logger Run with the particle logger.
Simulation meta-options:
--eagle Run with all the options needed for the
EAGLE model. This is equivalent to --hydro
--limiter --sync --self-gravity --stars
--star-formation --cooling --feedback
--black-holes --fof.
Control options:
-a, --pin Pin runners using processor affinity.
-d, --dry-run Dry run. Read the parameter file, allocates
memory but does not read the particles
from ICs. Exits before the start of time
integration. Checks the validity of
parameters and IC files as well as memory
limits.
-e, --fpe Enable floating-point exceptions (debugging
mode).
-f, --cpu-frequency=<str> Overwrite the CPU frequency (Hz) to be
used for time measurements.
-n, --steps=<int> Execute a fixed number of time steps.
When unset use the time_end parameter
to stop.
-o, --output-params=<str> Generate a parameter file with the options
for selecting the output fields.
-P, --param=<str> Set parameter value, overiding the value
read from the parameter file. Can be used
more than once {sec:par:value}.
-r, --restart Continue using restart files.
-t, --threads=<int> The number of threads to use on each MPI
rank. Defaults to 1 if not specified.
-T, --timers=<int> Print timers every time-step.
-v, --verbose=<int> Run in verbose mode, in MPI mode 2 outputs
from all ranks.
-y, --task-dumps=<int> Time-step frequency at which task analysis
files and/or tasks are dumped.
--cell-dumps=<int> Time-step frequency at which cell graphs
are dumped.
-Y, --threadpool-dumps=<int> Time-step frequency at which threadpool
tasks are dumped.