1 1 4 VisIt is a richly featured, turnkey application • VisIt is an open source, end user visualization and analysis tool for simulated and experimental data – Used by: physicists, engineers, code developers, vis experts – >100K downloads on web • R&D 100 award in 2005 • Used “heavily to exclusively” on 8 of world’s top 12 217 pin reactor cooling simulation. Run on ¼ of Argonne BG/P. 1 billion grid points
VisIt is a richly featured, turnkey application. 1 billion grid points. VisIt is an open source, end user visualization and analysis tool for simulated and experimental data Used by: physicists, engineers, code developers, vis experts >100K downloads on web R&D 100 award in 2005 - PowerPoint PPT Presentation
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VisIt is a richly featured, turnkey application
• VisIt is an open source, end user visualization and analysis tool for simulated and experimental data
– Used by: physicists, engineers, code developers, vis experts
– >100K downloads on web
• R&D 100 award in 2005• Used “heavily to exclusively” on 8
of world’s top 12 supercomputers
217 pin reactor coolingsimulation. Run on ¼ of Argonne BG/P.
1 billion grid points
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Terribly Named!! Intended for more than just visualization!
Data Exploration
VisualDebugging Quantitative Analysis
Presentations
=?
Comparative Analysis
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VisIt has a rich feature set that can impact many science areas.
Meshes: rectilinear, curvilinear, unstructured, point, AMR Data: scalar, vector, tensor, material, species Dimension: 1D, 2D, 3D, time varying Rendering (~15): pseudocolor, volume rendering,
thresholding, restrict to box, reflect, project, revolve, … File formats (~85) Derived quantities: >100 interoperable building blocks
+,-,*,/, gradient, mesh quality, if-then-else, and, or, not Many general features: position lights, make movie, etc Queries (~50): ways to pull out quantitative information,
debugging, comparative analysis
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VisIt employs a parallelized client-server architecture.
The VisIt team focuses on making a robust, usable product for end users.
Manuals• 300 page user manual• 200 page command line interface manual• “Getting your data into VisIt” manual
Wiki for users (and developers) Revision control, nightly regression testing, etc Executables for all major platforms Day long class, complete with exercises
Slides from the VisIt class
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VisIt is a vibrant project with many participants.
Over 50 person-years of effort Over one million lines of code Partnership between: Department of Energy’s Office of Nuclear
Energy, Office of Science, and National Nuclear Security Agency, and among others
2004-6
User communitygrows, includingAWE & ASC Alliance schools
Fall ‘06
VACET is funded
Spring ‘08
AWE enters repo
2003
LLNL user communitytransitioned to VisIt
2005
2005 R&D100
2007
SciDAC Outreach Center enablesPublic SW repo
2007
Saudi Aramcofunds LLNL to support VisIt
Spring ‘07
GNEP funds LLNL to support GNEP codes at Argonne
Summer‘07
Developers from LLNL, LBL, & ORNLStart dev in repo
‘07-’08
UC Davis & UUtah research done in VisIt repo
2000
Project started
‘07-’08
Partnership withCEA is developed
2008
Institutional supportleverages effort from many labs
Spring ‘09
More developersEntering repo allthe time
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VisIt: What’s the Big Deal?
Everything works at scale Robust, usable tool Vis to code development to scientific insight
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● Weak scaling study: ~62.5M cells/core
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#coresProblem Size
ModelMachine
8K0.5TIBM P5Purple
16K1TSunRanger
16K1TX86_64Juno
32K2TCray XT5JaguarPF
64K4TBG/PDawn
16K, 32K1T, 2TCray XT4Franklin
VisIt was recently demonstrated to show good performance at unprecedented scales.
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Three Ways To Get Data Into VisIt
(1) Write to a known output format (2) Write a plugin file format reader (3) Integrate VisIt “in situ”
• “lib-VisIt” is linked into simulation code (Note: Memory footprint issues with
implementation!)• Use model:
simulation code advances at some time interval (e.g. end of cycle), hands
control to lib-VisIt. lib-VisIt performs vis & analysis tasks, then hands
control back to simulation code repeat 9
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Tutorial schedule
10 minute overview (done) 6 part tutorial on using VisIt
• Introduction• Data analysis / expressions• Scripting• Moviemaking• Comparisons• Alternate data representations
Data model overview Database plugin development example Operator plugin development example Presentation on VisIt architecture / parallel algorithms
- Decision of when to pass or read is simplified here and based on load of processors owning data. - Heuristic weights against I/O, but allows for redundant I/O- All coordination done by slave masters.
This analysis depended on improvements in parallel particle advection
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AMR is handled natively in VisIt
VisIt understands:• Nesting of patches / Boundaries between patches
Strategy:• Each patch is processed separately• After reading data, subsequent passes to:
Identify coarse elements that are refined and mark them as “ghost”
Create ghost layers around outer boundaries (needs work)
UI: • Color by patch, color by level• Remove / show patches, levels • Have appropriate info returned for picks
Users need to reference their data “as they know it”.
Many different decompositions of data:• By simulation processor ID• By material• By part in an assembly• By level/patch for AMR• Plus key subsets, nodes/elements representing:
Boundary conditions Slide surfaces ProbesWe need to allow users to cull away
unneeded subsets of the data.
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Representing data relationships
Relationships between many decompositions are complicated.
Need sophisticated machinery to store this knowledge. Machinery must be customizable to give right “look and