VisIt is an open source, turnkey application for visualization and analysis of
large scale simulated and experimental data sets.
It leverages several third-party libraries such as the Qt widget library for
its user interface, the Python programming language for a command line
interpreter, and the Visualization ToolKit (VTK) for its data model and
The preferred way to use VisIt on Nautilus is to take advantage of its client/
server architecture and run a VisIt client locally while connecting to the
server running on Nautilus.
Binary executables can be downloaded from the
When installing VisIt locally, you can choose a particular site configuration.
The NICS configuration will provide you with the host profiles you need to
connect to Nautilus as a remote host.
To connect to Nautilus when running VisIt on your local machine, simply choose
Nautilus from the 'Host' menu in the 'Open' dialog. You will be asked for your
passcode. Now you should be able to navigate to your files on Nautilus.
When you choose to open a file, you will be presented a dialog for launching
VisIt's parallel engine.
Here, you can choose the number of cores you wish to use. VisIt then
launches its parallel engine on Nautilus behind the scenes and you can explore
your data interactively on your local machine.
Since VisIt can be scripted with Python, it can be run without its GUI or
Viewer components, directly on Nautilus.
You must first load VisIt with the module command:
> module load visit
To launch a parallel VisIt job from the login node, you must use the
VisIt flags '
-l' to specify the launch method and '
-np' to specify number of
cores. For example:
> visit -nowin -cli -s my_script.py -l qsub/mpirun -np 64
will automatically launch a job for 64 cores to run
my_script.py using VisIt's
To specify other PBS options with the VisIt command line, use these VisIt
|Partition (queue) to run in
|Bank (account) to charge
|Name for job
For a complete list of VisIt options, do:
> visit -fullhelp
From within a PBS batch script, the '
-l' flag is not needed--only specify
the number of cores with '
-np'. Here's an example script to use 64 cores:
#PBS -l ncpus=64,walltime=03:00:00
#PBS -A XXXYYY
module load visit
visit -nowin -cli -s my_script.py -np 64
Many examples of scripting VisIt with Python can be found on the