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Article #1021

Re: NAG routine D02BAF uses runge-kutta-MERSON ??

#1021
From: Mike Hosea
Date: Tue, 05 Jan 1993 17:31
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In article <1ia4m9INN2h2@rave.larc.nasa.gov> makarand@gazelle.larc.nasa.gov (Makarand A. Kulkarni) writes:
>Most error estimates for integrators are based on what is called
>the "linear test equation". It is extremely difficult if not
>impossible to obtain local truncation error estimates for 
>nonlinear problems. Normally error estimates for nonlinear
>problems are obtained by linearizing the equation(s).

If I understand you correctly, this isn't true.  Error estimators 
for integrators are usually based on subtracting a higher order 
result from a lower order result to get an asymptotically correct
estimate of the error in the lower order result.  The technique is
valid for linear and nonlinear problems.   

You must be thinking about linear vs. general (nonlinear) stability
analysis, since the "linear test equation" is used in that context,
and general (nonlinear) stability analysis is a lot harder than 
the linear stability analysis.
-- 
Regards,
Mike Hosea (mhosea@seas.smu.edu)
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Path: arc1-ca.pugleaf.net!sparky!uunet!seas.smu.edu!mhosea
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Newsgroups: sci.math.num-analysis
Path: arc1-ca.pugleaf.net!sparky!uunet!seas.smu.edu!mhosea
From: mhosea@seas.smu.edu (Mike Hosea)
Subject: Re: NAG routine D02BAF uses runge-kutta-MERSON ??
Message-ID: <1993Jan5.173151.21651@seas.smu.edu>
Keywords: Merson, nonlinear problems
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Organization: SMU - School of Engineering & Applied Science - Dallas
References: <1993Jan4.141352.5937@fys.ruu.nl> <1ia4m9INN2h2@rave.larc.nasa.gov>
Date: Tue, 5 Jan 1993 17:31:51 GMT
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