What is Installed with VSim?

Upon completing the installation process (described in VSim Installation Instructions), VSimComposer, the VSim Computation Engine, Python, and MPI will be installed on your computer. These are described in detail below.


VSimComposer is a graphical user interface for

  • Creating and editing VSim input files

  • Executing VSim

  • Analyzing VSim generated data

  • Visualizing VSim generated data

  • Viewing the documentation.

The VSimComposer editor and validator have built-in functions and graphical components that help you to create input files. Example input files, ranging in complexity from beginning to advanced, are included with VSimComposer. New VSim users can use these examples as templates. Advanced VSim users can use VSimComposer to validate the syntax of their own input files, whether their files have been created using VSimComposer or by using a text editor.

The VSimComposer Run pane invokes the VSim engine with user definable settings for number of steps, number of data dumps, and restart file, if any. It also allows selection of serial versus parallel VSim.

VSimComposer now allows selection of analysis programs, either supplied with VSim or user written.

The visualization in VSimComposer is provided by the graphical analysis tool VisIt (see https://wci.llnl.gov/codes/visit/). VisIt is embedded within VSimComposer. Data generated by VSim or by analysis programs automatically appears in the Visualization pane.

All documentation can be seen from within VSimComposer, fully cross-referenced.

VSim Computational Engine

The VSim computational engine runs both as a serial (vorpalser) and parallel (vorpal) application for multi-processor / multi-core systems that support MPI. VSim now comes in the specialized VSim packages. The VSim computational engine is embedded within VSimComposer.


Python is an open-source, interpreted scripting language managed by the Python Software Foundation. For more information about Python (See http://www.python.org/).

VSim uses Python to process input files, allowing users to set up simulations with math functions, variable substitutions, and macros.

VSim uses its own embedded version of the Python interpreter to pre-process input files and execute any Python code in an input file.


The Message Passing Interface (MPI) is an application programming interface (API) for communicating between processes that execute in parallel. There are many implementations. The Linux and Mac versions come with the OpenMPI (See http://www.open-mpi.org/) implementation of MPI. The Windows versions come with the Microsoft MPI implementation The appropriate MPI implementation is embedded within VSimComposer.

More Information

More information about VSim can be found at the VSim Product Website (https://www.txcorp.com/vsim). Send questions about installing or running VSim to Tech-X Customer Support at support@txcorp.com.

Extensive assistance in the use of VSim or simulation in general is available from Tech-X Professional Services. Please contact Tech-X directly for sales, consulting, and other questions at sales@txcorp.com.