N-body problem integration (N=4: one star, one heavy planet and one light planet with a satellite) computed with 3 different optimization options on the same computer (sensitivity to rounding-off errors) (Integration du probleme des N-corps (N=4: une etoile, une planete lourde et une planete legere avec un satellite) calcule avec 3 options d'optimisation differentes (sensibilite aux erreurs d'arrondi)) {a chapter of 'Mathematics - A Virtual Instrument For Exploring Space Time And Beyond'}

N-body problem integration (N=4: one star, one heavy planet and one light planet with a satellite) computed with 3 different optimization options on the same computer (sensitivity to rounding-off errors) [Intégration du problème des N-corps (N=4: une étoile, une planète lourde et une planète légère avec un satellite) calculé avec 3 options d'optimisation différentes (sensibilité aux erreurs d'arrondi)].

The same program is compiled 3 times with 3 different optimization options and then is run with exactly the same initial conditions -see bottom left picture- (the computer used is a SGI Power-Challenge M -75 MHz R8000 Processor- under IRIX 6.2 with C 7.0):

results obtained with the "-O1" option are visualized using Red spheres,
results obtained with the "-O2" option are visualized using Green spheres,
results obtained with the "-O3" option are visualized using Blue spheres.

In this example, "-O1" et "-O2" give the same forecasts (Red+Green = Yellow), when "-O3" (the most aggressive optimization) gives very different results.

(CMAP28 WWW site: this page was created on 02/04/1997 and last updated on 06/04/2026 22:59:24 -CEST-)

[See all related pictures (including this one) [Voir toutes les images associées (incluant celle-ci)]]

[Go back toMathematics - A Virtual Instrument For Exploring Space Time And Beyond [Retour à {a chapter of 'Mathematics-AVirtualInstrumentForExploringSpaceTimeAndBeyond'}]]

[The Y2K Bug [Le bug de l'an 2000]]
[Are we ready for the Year 2038 [Notre informatique est-elle prête pour l'An 2038]?]

[Site Map and Help [Plan du Site et Aide]]
[Mail [Courrier]]
[About Pictures and Animations [A Propos des Images et des Animations]]

Copyright © Jean-François COLONNA, 1997-2026.
Copyright © France Telecom R&D and CMAP (Centre de Mathématiques APpliquées) UMR CNRS 7641 / École polytechnique, Institut Polytechnique de Paris, 1997-2026.

Copyright © Jean-François COLONNA, 1997-2026. Copyright © France Telecom R&D and CMAP (Centre de Mathématiques APpliquées) UMR CNRS 7641 / École polytechnique, Institut Polytechnique de Paris, 1997-2026.

Copyright © Jean-François COLONNA, 1997-2026.
Copyright © France Telecom R&D and CMAP (Centre de Mathématiques APpliquées) UMR CNRS 7641 / École polytechnique, Institut Polytechnique de Paris, 1997-2026.