VO Application interoperability study

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VO Applicationinteroperability study
VOApp.compareTo(PLASTIC)

• Pierre Fernique
• CDS

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The goal

• Cross correlate data by using simultaneously
  collaborative VO applications
• Requirements
• Data transfer mechanisms
• Cross selection objects/regions
• and a large screen !

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Example VOPlot/Aladin cross selections
VOPlot reddest objects selections correspond to
the Aladin dense regions
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Some solutions

• Without cross-selection ? usual solution
• Via files Save and load gt data standards
  (FITS and VOTable)
• Via a Copy and paste function gt data standards
  (OS dependent)
• With cross-selection ? dedicated solution
• VOApp java interface (new ExtApp version)
• PLASTIC hub

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The technical choices

• PLASTIC
• A local daemon (HUB)
• Events by sockets predefined messages (via RMI
  or XML-RPC)

• VOApp
• Unique java virtual machine
• Events by method calls (via a Java interface )

API
One java machine
VOPlot
PlasticHub
VOApp
VOApp
API
API
Topcat
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VOApp / Plastic implementations
VOApp PLASTIC
Aladin Java Yes Yes
APT (STScI HST tool) Java Yes No
AstroGrid tools Java No Yes (Astroscope, VAST,)
CADC prototype Java Yes (ExtApp) No
Topcat Java Yes (ExtApp) Yes
VisIVO C No Yes
VOPlot Java Yes (ExtApp) No
VOSpec Java No Yes
XSA (ESA XMM access tool) java Yes (ExtApp) No
Xmdv-tool Java No Yes
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VOApp.compareTo(PLASTIC)
VOApp PLASTIC
Send images/tables Yes Yes
Get images/tables Yes No
Cross object selections Yes Yes
Cross image selections Yes pointing / No - regions Yes pointing / No - regions
Dynamic listeners (ex mouseMove) Yes (gt250 000 events per sec) Yes (lt200 events per sec)
Sharing memory (for avoiding object/image dupplications) No (Why not ?!) No
script messages (ie opened interface) Yes No (Why not ?!)
Capabilities
Multi-machine nodes No (in the same JVM) No (Why not ?!)
Multi-language No (only java) Yes (via RMI and XMLRPC)
Multi-clients Yes (but 1 to 1 oriented) Yes (real broadcast facility)
Easy packaging No (both applications should be library compatibles) Yes
Easy user usage Yes Yes/No (Hub launching issue ?)
Implementation
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Who ?

• VOApp
• P.Fernique, F. Ochsenbein CDS
• S. Kale VO-India
• T. Donalson STScI
• ?http//aladin.u-strasbg.fr/java/FAQ.html
  VOApp

• PLASTIC
• J. Taylor, M. Taylor, N. Wistansley Astrogrid
• T.Boch CDS
• M. Comparato INAF
• ? http//plastic.sourceforge.net

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Which one ?

• PLASTIC
• ? multi-language
• ? generic collaborations
• ? Certainly a good candidate for a new VO
  standard.

• VOApp
• ? only in Java world
• ? dedicated collaborations
• ? high performances

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Comments ?