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ID:33928440
大小:186.69 KB
页数:8页
时间:2019-02-28
《design and implementation of a scalable parallel direct solver for sparse symmetric positiv》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、DesignandImplementationofaScalableParallelDirectSolverforSparseSymmetricPositiveDeniteSystems:PreliminaryResultsyyzzAnshulGuptaFredGustavsonMaheshJoshiGeorgeKarypiszVipinKumarAbstractSolvinglargesparsesystemsoflinearequationsisatthecoreofmanyproblem
2、sinengineeringandscienticcomputing.Ithaslongbeenachallengetodevelopparallelformulationsofsparsedirectsolversduetoseveraldierentcomplexstepsinvolvedintheprocess.Inthispaper,wedescribeoneoftherstecient,practical,androbustparallelsolversforsparsesymm
3、etricpositivedenitelinearsystemsthatwehavedevelopedanddiscussthealgorithmicandimplementationissuesinvolvedinitsdevelopment.1IntroductionSolvinglargesparsesystemsoflinearequationsisattheheartofmanyengineeringandscienticcomputingapplications.Therearet
4、womethodstosolvethesesystems-directanditerative.Directmethodsarepreferredformanyapplicationsbecauseofvariouspropertiesofthemethodandthenatureoftheapplication.Awideclassofsparselinearsystemsarisinginpracticehaveasymmetricpositivedenite(SPD)coecientma
5、trix.TheproblemistocomputethesolutiontothesystemAx=b;whereAisasparseandSPDmatrix.SuchasystemiscommonlysolvedusingCholeskyfactorization.Adirectmethodofsolutionconsistsoffourconsecutivephasesviz.ordering,symbolicfactorization,numericalfactorizationandso
6、lutionoftriangularsystems.Duringtheorderingphase,TapermutationmatrixPiscomputedsothatthematrixPAPwillincuraminimalllduringthefactorizationphase.Duringthesymbolicfactorizationphase,thenon-zerostructureofthetriangularCholeskyfactorLisdetermined.Thesymb
7、olicfactorizationphaseexistsinordertoincreasetheperformanceofthenumericalfactorizationphase.ThenecessaryoperationstocomputethevaluesTTinLthatsatisfyPAP=LL,areperformedduringthephaseofnumericalfactorization.Finally,0thesolutiontoAx=biscomputedbysolving
8、twotriangularsystemsviz.Ly=bfollowedbyT000Lx=y,whereb=Pbandx=Px.Solvingtheformersystemiscalledforwardeliminationandthelatterprocessofsolutioniscalledbackwardsubstitution.Thenalsolution,x,isobtainedT0usingx=Px.Inthispaper,wedescribeoneofthers
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