Looking at the output
The snapshots are binary, so you need something that understands the format. The usual choice is SPLASH.
Installing SPLASH
Two guides in the repository cover this, and there is no point repeating them:
Data_visualization/Readme.md is a step-by-step walkthrough written for StarSmasher users, including building giza, which SPLASH needs and does not ship.
Section 3 of documentation/installation.md covers a system-wide install and the
libgiza.soproblems that follow one.
Reading StarSmasher snapshots
SPLASH has a StarSmasher reader built in:
splash -f starsmasher out*.sph
If your SPLASH predates it, Data_visualization/read_data_jamiesph.f90 is the
reader, with a Makefile beside it.
The examples in example_input ship splash.defaults and splash.units.
Copy them into your run directory before starting SPLASH and it will open with
sensible axes and units rather than raw code units.
What to look at
For a relaxation, the useful comparison is not a picture but a profile.
Plot pressure, density, particle mass, smoothing length and neighbour number
against radius, for parent.sph and for col0000.sph together: that shows
how well the initial particle layout matched the profile it was asked to
reproduce. Repeat with a later col file to see what the relaxation did. The
radial components of the hydrodynamic and gravitational accelerations are worth
adding: in a settled model they mirror each other, and where they do not, the
star is not in equilibrium. See Relaxing a star.
For a collision, the snapshots are the point. Column density in the orbital
plane over successive out files shows the encounter, and energy0.sph
tells you whether to trust it. See Output files.
Note
A picture can look convincing while the model is poor. Check the profiles and the energy trace as well as the image.
Other tools
splot_routines in the repository contains analysis scripts, including
routines for masses, orbits and spins.