Srinivasa Ramanujan et PI !

Cet article parle de la méthode de Srinivasa Ramanujan pour calculer PI.
La formule, découverte par Ramanujan lui-même vers 1910, est très drôle : en fait, elle calcule à chaque itération 8 nouveaux chiffres. Le programme Java que j'ai écrit utilise la précision des doubles, codés sur 8 octets.
Sur les impressions d'écrans ci-jointes, vous trouverez le code en Java des méthodes fact() et formula(), la première renvoie le factoriel d'un entier, la seconde renvoie la valeur de PI pour n donné. Vous trouverez aussi la formule de Srinivasa pour PI extraite de wikipedia.org, et une imprime écran de mon application Java, programmée avec NetBeans 6.0 sous Linux.

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