1、The FreeHEP Java Library http:/java.freehep.org,ACAT 2000 Fermilab October 2000,Mark Donszelmann, Julius Hrivnac CERN Gary Bower, Tony Johnson, Joseph Perl - SLAC Charles Loomis UC Santa Cruz,What is Freehep library,Started as a convergence of WIRED Java Analysis Studio (JAS) A common base library m
2、inimize unnecessary duplication of work maximize code reuse Soon realized many others working on Java Now have contributions from Atlas, Babar and US Linear Collider Detector (LCD) Others welcome to contribute Today - a library of HEP-wide Java software Some very HEP specific (c.f. CLHEP) Some gener
3、al purpose utilities,Goals,Open source All code and documentation in CVS, web browsable All code licensed under LGPL to make it freely reusable Preview area for partly-baked ideas Minimal interdependence between packages Take what you like, leave what you dont. Pure Java where possible We include so
4、me C+ code In particular tools for helping Java and C+ to co-exist,Why Java?,We enjoy writing Java code OO, highly portable Maximizes programmer effectiveness No need to deal with memory leaks, core dumps, corrupted pointers Frees developer to concentrate on clean OO design Java makes code reuse eas
5、y Use interfaces to separate interfaces and implementation Can support 1 implementation of same functionality No problem with incompatible base libraries,Isnt Java too slow?,No! Huge advances have been made in last 4 years Dynamic code optimization Optimizes code while it is running Java now gives a
6、verage of 60% of C+ performance Java performance continues to improve Static optimization (C+) is mature no improvement expected,What does it contain?,Non-HEP specific 2D Vector Graphics generates .eps, .svg, Studio Hep Studio JACO Java access to C+ Objects Jneeds java package dependency HEP specifi
7、c hep.physics package 3-vector, 4-vectors and utilities Jet Finding, Event Shape routines Diagnostic Event Generator Yappi XML Particle Property Database hep.io STDHEP, Root AIDA interface HepRep HEP3D,2D Graphics Package,Java contains machine independent graphics Advanced 2D graphics Built-in suppo
8、rt for printing Freehep 2D graphics adds support for Saving graphics in vector graphics format Encapsulated Postscript (eps) Clean output can be hand edited if necessary Scalable vector graphics (svg) Easily extensible for other vector graphics formats General graphics export Supports vector and pix
9、el graphics (GIF, JPG, PNG) Easily extensible for other formats (e.g. XML),(HEP) Studio,Studio Common Base GUI for JAS + Wired + XML Menus Command Dispatch mechanism Plugin Architecture Flexible MDI type GUI Save/Restore state via XML HEP Studio Adds event access Random or Sequential Remote or Local
10、,JACO (Java Access to C+ Objects),Interoperability of Java and C+ is certainly possible But tedious Code must be written for each method Need to deal with starting JavaVM Need to deal with object lifetimes JACO Aims to solve this Automatic generation of glue code Small library to deal with details A
11、imed at Event Display and Event Analysis,.hh files,RTTI,Parser,Code Generator,.java,.hh,.cc,Runtime Library,hep.physics,3-vectors, 4-vectors, utilities Interface and basic implementation Event Shape utilities Jet finder framework Supports many different algorithms User extensible Diagnostic Event Ge
12、nerator Framework for event generation Can support Java or Fortran/C+ generators,YaPPi,Java API for accessing particle properties Full API for access to all data Particle Property Provider Simpler interface suitable for analysis and MC programs XML format for storing Particle Properties, Decay Modes
13、 and Branching Ratios Supports all data from PDG book Numeric and non-numeric data Allows one of more XML files to be merged Supports user-supplied XML files Utilities Perl(!) script for parsing PDG postscript files Generates XML files for entire book (in progress) Servlet to publish data via Web,HE
14、P IO,Uses: Event Display, Analysis tools, Event Generators StdHep Complete implementation of basic StdHEP IO Interoperable with Fortran/C implementation Supports reading and writing Root IO Initial implementation read-only Supports (de)compression, random access, StreamerInfo Support for reading TTr
15、ees not yet complete Goal is complete read/write access to Root IO Including Trees, Automatic splits, pointer following etc.,AIDA,AIDA = Abstract Interface for Data Analysis Isolates analysis/reconstruction program from histogram package Can change from one package to another without changing code.
16、FreeHEP contains Java AIDA interface specification Java reference implementation C+ Java mapping,Java Program,A I D A,Java AIDA Implementation,C+ Program,A I D A,C+ AIDA Implementation,Java AIDA Implementation,C+ Program,A I D A,A I D A,C+ - Java,HepRep,Experiment independent graphics representables
17、 Can be moved from server to client File access, Direct or Client-Server mode: XML, JHepRep, RMI, or CORBA. Easy to add new representations for Event Display Allows experiment independent Event Display client Can be mapped to different displays EG Wired, Java 3D JHepRep/C+ interface allows HepReps t
18、o be created from C+ Geant 4 interface,HEP3D,Java 3D Primitives for Geant4 volumes G4Box G4Cons G4Para G4Polycone G4Polyhedra G4Sphere G4Trap G4Trd G4Tubs Support for switching between wireframe and solid shapes,Future Possibilities?,ZVTOP Topological vertex finding Being worked on by Wolfgang Walko
19、wiak TRF+ - general purpose tracking package Being worked on by Norm Graf Other reusable reconstruction algorithms Clustering Kalman Filter General purpose fitting framework General purpose plotter,More Info?,How do I get it? http:/java.freehep.org All source code is in CVS Browse it on the web, or
20、download with your favorite CVS client All software distributed under Lesser GNU Public License (LGPL) Manuals Automatically generated documentation (javadoc) Updated every 15 minutes Pre-built libraries (jar files) How can I contribute Contact any of the authors or e-mail developersfreehep.org,Conclusion,Warning! Different sections of library are in different stages of completion Some packages have been in use for some time Some are still under development Try it, give us feedback Dont waste time with Core dumps Memory leaks Subtle debugging problems Join the HENP Java revolution!,
