== VisIt
[[PageOutline]]

[[Image(https://wci.llnl.gov/content/assets/images/simulation/computer-codes/visit/visit-home.jpg, align=right)]]

"VisIt was originally developed by the Department of Energy (DOE) Advanced Simulation and Computing Initiative (ASCI) to visualize and analyze the results of terascale simulations. It was designed with a high degree of modularity to support rapid deployment of new visualization technology. This includes a plugin architecture for custom readers, data operators and plots as well as the ability to support multiple different user interfaces. Following a prototyping effort in the summer of 2000, an initial version of VisIt was developed and released in the fall of 2002. Since then, over 100 database readers, 60 operators and 20 plots have been added to the open source code. In addition, commercial, government and academic organizations in the US, Europe and elsewhere have developed and maintained proprietary plugins and user interfaces for their own needs. Although the primary driving force behind the original development of VisIt was for visualizing ASCI terascale data, VisIt has also proven to be well suited for visualizing smaller scale data from simulations on desktop systems. Because of its applicability beyond visualizing terascale data, we are making VisIt freely available as a BSD licensed open source product."
[https://wci.llnl.gov/simulation/computer-codes/visit link]

 * VisIt Homepage (https://visit.llnl.gov)
 * VisIt Manuals (https://wci.llnl.gov/simulation/computer-codes/visit/manuals)
 * VisIt Prebuild Executables (https://wci.llnl.gov/simulation/computer-codes/visit/executables)
 * VisIt Wiki (http://visitusers.org)


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=== In-Situ Visulalization with VisIt
[[Image(visit_libsim.png, 180px, align=right)]]
"VisIt provides a library for in-situ visualization and analysis that is called libsim. \\
Libsim lets you instrument your simulation code so VisIt can connect to it and access its data directly as though the simulation was a VisIt compute engine." [http://www.visitusers.org/index.php?title=VisIt-tutorial-in-situ link]

Ok, what do you have to do:
 * check this presentation [http://www.visitusers.org/images/1/10/SC2010-in-situ.pdf pdf]
 * instrument your code
   * Fortran90 example (from [http://www.fz-juelich.de/ias/jsc/EN/Expertise/High-Q-Club/psOpen/_node.htm psOpen]): [https://trac.version.fz-juelich.de/vis/attachment/wiki/VisIt/psopen_visit.F90 psOpen_visit.F90]
 * link your code with libsim
 * start simulation
 * connect with GUI to simulation

You need more details? - here you go:

 [wiki:VisIt_runon_Jureka  => ... on JUREKA] \\
 [wiki:VisIt_runon_Juqueen => ... on JUQUEEN]

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=== Build VisIt
VisIt is prebuild for you. \\
You can find it [https://wci.llnl.gov/simulation/computer-codes/visit/executables here].

Ok, you want to build it myself:

 [wiki:VisIt_build_x86     => ... for general x86] \\
 [wiki:VisIt_build_Jureka  => ... for JUREKA] \\
 [wiki:VisIt_build_Juqueen => ... for JUQUEEN]

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=== General Links
VisIt Homepage: https://visit.llnl.gov \\
VisIt Wiki: http://visitusers.org \\
VisIt Gallery: https://wci.llnl.gov/simulation/computer-codes/visit/gallery \\

=== Libsim Links
Libsim: http://www.visitusers.org/index.php?title=Category:Libsim \\
Libsim Status: http://www.visitusers.org/index.php?title=Additional_in-situ_work \\

=== JSC Presentations
In-Situ Visualization (23.06.2015): [https://trac.version.fz-juelich.de/vis/raw-attachment/wiki/VisIt/InsituVis-Goebbert-23-06-2015.pdf pdf]


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any feedback welcomed - h.zilken@fz.juelich.de, goebbert@jara.rwth-aachen.de