Not Invented Here: Not Invented Here: The Re-use of Commercial The Re-use of Commercial

Components in HEP ComputingComponents in HEP Computing

Jeremy WaltonThe Numerical Algorithms Group Ltd,

UK

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OverviewOverview• Changing priorities for HEP development

– Build? Buy?

• Commercial supply of software– NAG - an introduction

• Commercial components in LHC++– what and where

• Feedback from HEP– HEP/NAG synergy, technology transfer– Ongoing commercial development

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Development in LHC eraDevelopment in LHC era• Large Hadron Collider at CERN

– Expected to enter production in 2005– Data analysis will continue beyond 2020 – Total data volume ~ 100PB

• Evolution of CERNLIB– move from mainframe to distributed computing– move from Fortran to object-oriented language– Investigation of alternatives to internal

development

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The LHC++ suiteThe LHC++ suite• Tools for storing and analysing HEP data• Provides CERNLIB functionality in C++• Re-uses existing work – where possible

– e.g. CLHEP

• Uses standard solutions – where appropriate– e.g. OpenGL, STL, …

• Based on commercial components – where applicable

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Why not build?Why not build?• Reduced HEP development resources• Support and maintenance issues

– e.g. CERNLIB support continues to (~ 2003/6)

• Timescale considerations– Limited lifetime of developers– Long lifetime of LHC

• Make most appropriate use of resource– Only build what’s necessary– Build on components from elsewhere

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Numerical Algorithms GroupNumerical Algorithms Group• Commercial scientific software company

– Offices in Oxford, Munich, Chicago, Tokyo

• First numerical library developed in 1971– > 1,000 routines, > 10,000 users worldwide

• Other products and services– statistics, visualisation, symbolics, simulation

• Collaborative development model– with experts, with customers

• Not-for-profit company (in UK)

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LHC++ commercial componentsLHC++ commercial components• NAG C Library

– collection of reliable and robust routines for• linear algebra• optimisation• PDEs, ODEs• FFTs• Correlation, regression• multivariate methods

– Strong overlap with HEP requirements

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LHC++ commercial componentsLHC++ commercial components• Open Inventor

– Object-oriented 3D graphics library– Uses OpenGL for rendering– Defines standard 3D file format– Extensible

• IRIS Explorer– Modular visualisation toolkit– Strong support for distributed applications– Uses NAG C Library, Open Inventor, OpenGL

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Building on componentsBuilding on components• HEPInventor

– HEP presentation graphics library– Based on Open Inventor– Graphics requirements from PAW

• axes, histograms, page layout, printing

• HEP Explorer– HEP-specific IRIS Explorer modules– Focussed on interactive analysis

• histograms, Ntuple-like analysis, fitting

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HEP Explorer in LHC++HEP Explorer in LHC++

Event browser

Histogram plotter

Display

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Feedback from HEP to NAGFeedback from HEP to NAG• MINOS error calculation required

– being added to new NAG minimizers

• Support for CERNLIB special functions– being added to NAG C Library

• Better 1D (histogram) plotting– Now part of IRIS Explorer 4.0

• Porting to Linux– IRIS Explorer 4.0 now available

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HEP/NAG synergyHEP/NAG synergy• Better NAG support of HEP features

– Frees HEP development and support resource– Improves coverage of NAG products elsewhere

• Ongoing process– Collaborative development model– Long-term relationship– Timescale considerations

• Important relationship for NAG