From: zianekhodja Date: Sat, 16 Jan 2016 13:53:42 +0000 (+0100) Subject: relecture section III A X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/kahina_paper2.git/commitdiff_plain/87920647de834836776958ae2479e1e91567ab76?ds=sidebyside relecture section III A --- diff --git a/paper.tex b/paper.tex index 489b65b..a790787 100644 --- a/paper.tex +++ b/paper.tex @@ -663,24 +663,24 @@ z^{k+1}_{i}=z_{i}^{k}-\frac{\frac{p(z_{i}^{k})}{p'(z_{i}^{k})}} {1-\frac{p(z_{i}^{k})}{p'(z_{i}^{k})}\sum_{j=1,j\neq i}^{j=n}{\frac{1}{(z_{i}^{k}-z_{j}^{k})}}}, i=1,\ldots,n \end{equation} -This method contains 4 steps. The first step consists of the initial -approximations of all the roots of the polynomial. The second step -initializes the solution vector $Z$ using the Guggenheimer -method~\cite{Gugg86} to ensure the distinction of the initial vector -roots. In step 3, the iterative function based on the Newton's -method~\cite{newt70} and Weiestrass operator~\cite{Weierstrass03} is -applied. With this step the computation of roots will converge, -provided that all roots are different. +This method contains 4 steps. The first step consists of the initial approximations of all the roots of the polynomial.\LZK{Pas compris??} +The second step initializes the solution vector $Z$ using the Guggenheimer method~\cite{Gugg86} to ensure the distinction of the initial vector roots.\LZK{Quelle est la différence entre la 1st step et la 2nd step? Que veut dire " to ensure the distinction of the initial vector roots"?} +In step 3, the iterative function based on the Newton's method~\cite{newt70} and Weiestrass operator~\cite{Weierstrass03} is applied. With this step the computation of roots will converge, provided that all roots are different.\LZK{On ne peut pas expliquer un peu plus comment? Donner des formules comment elle se base sur la méthode de Newton et de l'opérateur de Weiestrass?} +\LZK{Elle est où la 4th step??} +\LZK{Conclusion: Méthode mal présentée et j'ai presque rien compris!} In order to stop the iterative function, a stop condition is applied. This condition checks that all the root modules are lower -than a fixed value $\xi$. +than a fixed value $\epsilon$. \begin{equation} \label{eq:Aberth-Conv-Cond} -\forall i \in [1,n];\vert\frac{z_{i}^{k}-z_{i}^{k-1}}{z_{i}^{k}}\vert<\xi +\forall i\in[1,n],~\vert\frac{z_i^k-z_i^{k-1}}{z_i^k}\vert<\epsilon \end{equation} + +\LZK{On ne dit pas plutôt "the relative errors" à la place de "root modules"? Raph nous confirmera quelle critère d'arrêt a utilisé.} + \subsection{Improving Ehrlich-Aberth method} With high degree polynomials, the Ehrlich-Aberth method suffers from floating point overflows due to the mantissa of floating points