X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/Krylov_multi.git/blobdiff_plain/03b1aa97afc150a187a7ec819386a3b5768a2f9e..d9105f3cc518086be070a250845823a6ec0f7b4a:/krylov_multi.tex diff --git a/krylov_multi.tex b/krylov_multi.tex index 1010f07..0ff9175 100644 --- a/krylov_multi.tex +++ b/krylov_multi.tex @@ -6,6 +6,12 @@ \usepackage{algorithm} \usepackage{algpseudocode} +\algnewcommand\algorithmicinput{\textbf{Input:}} +\algnewcommand\Input{\item[\algorithmicinput]} + +\algnewcommand\algorithmicoutput{\textbf{Output:}} +\algnewcommand\Output{\item[\algorithmicoutput]} + \title{A scalable multisplitting algorithm for solving large sparse linear systems} @@ -55,8 +61,13 @@ solvers. However, most of the good preconditionners are not sclalable when thousands of cores are used. -A completer... -On ne peut pas parler de tout...\\ +Traditionnal iterative solvers have global synchronizations that penalize the +scalability. Two possible solutions consists either in using asynchronous +iterative methods~\cite{ref18} or to use multisplitting algorithms. In this +paper, we will reconsider the use of a multisplitting method. In opposition to +traditionnal multisplitting method that suffer from slow convergence, as +proposed in~\cite{huang1993krylov}, the use of a minimization process can +drastically improve the convergence. @@ -255,7 +266,9 @@ gradient method for the normal equations CGNR~\cite{S96,refCGNR}. \begin{algorithm}[!t] \caption{A two-stage linear solver with inner iteration GMRES method} \begin{algorithmic}[1] -\State Load $A_l$, $B_l$, initial guess $x^0$ +\Input $A_l$ (local sparse matrix), $B_l$ (local right-hand side), $x^0$ (initial guess) +\Output $X_l$ (local solution vector)\vspace{0.2cm} +\State Load $A_l$, $B_l$, $x^0$ \State Initialize the minimizer $\tilde{x}^0=x^0$ \For {$k=1,2,3,\ldots$ until the global convergence} \State Restart with $x^0=\tilde{x}^{k-1}$: \textbf{for} $j=1,2,\ldots,s$ \textbf{do}