NBODY4
is a sophisticated N-body code developed by
Dr.
Sverre Aarseth
to run with GRAPE-6 and GRAPE-6a hardware. It is a Hermite
individual time step code with two-body (KS) regularization and many other
features. NBODY4 is
described in Aarseth's book
Gravitational
N-body Simulations Tools and Algorithms, on
his
software
downloads page and in his
publications.
The NBODY4 code used in NBodyLab was downloaded
in February
2006, and further revisions were made in cooperation with Aarseth. NBODY4 is updated occasionally; see the
links above for the latest version and other well-known
codes such as NBODY6.
On a personal workstation, NBODY4 is run via a command line
interface and runs may last days or weeks for scientific research.
Vicki Johnson adapted NBODY4 for NBodyLab so that small runs could be
made via a web interface, enabling users who do not have GRAPE-6a
hardware to experiment with NBODY4's performance and capabilities. Vicki does not
have the expertise to fully validate her adaptation for NBodyLab, so
please email Vicki
if you would like to see improvements or have questions about the web interface.
The
NBODY4 code is driven by a single input parameter file with many
interesting options.
Aarseth has prepared an
introduction
to help you run and understand the
output from NBODY4 simulations.
Please print these for reference and carefully check your edits of
the input file. Also helpful is Aarseth's
book and the NBODY6 user manual, available at the
software
downloads page.
See
timing comparisons of NBODY4 with GRAPE acceleration versus
NBODY6 without GRAPE acceleration.
To sign up for news, get help or request permission for longer simulations,
write to nbodylab@interconnect.com.