X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/book_gpu.git/blobdiff_plain/44b8f845847505b81dc0f1199c49e67a495ed7a0..81003a055684f98759766a62391db14f48e0cbf4:/BookGPU/Chapters/chapter6/PartieAsync.tex diff --git a/BookGPU/Chapters/chapter6/PartieAsync.tex b/BookGPU/Chapters/chapter6/PartieAsync.tex index 44eadd5..4a2b6d2 100644 --- a/BookGPU/Chapters/chapter6/PartieAsync.tex +++ b/BookGPU/Chapters/chapter6/PartieAsync.tex @@ -15,34 +15,59 @@ Formally, if we denote by $f=(f_1,...,f_n)$ the function representing the iterative process and by $x^t=(x_1^t,...,x_n^t)$ the values of the $n$ elements of the system at iteration $t$, we pass from a synchronous iterative scheme of the form: +%% \begin{algorithm}[H] +%% \caption{Synchronous iterative scheme}\label{algo:ch6p2sync} +%% \begin{Algo} +%% $x^{0}=(x_{1}^{0},...,x_{n}^{0})$\\ +%% \textbf{for} $t=0,1,...$\\ +%% \>\textbf{for} $i=1,...,n$\\ +%% \>\>$x_{i}^{t+1}=f_{i}(x_{1}^t,...,x_i^t,...,x_{n}^t)$\\ +%% \>\textbf{endfor}\\ +%% \textbf{endfor} +%% \end{Algo} +%% \end{algorithm} \begin{algorithm}[H] \caption{Synchronous iterative scheme}\label{algo:ch6p2sync} - \begin{Algo} - $x^{0}=(x_{1}^{0},...,x_{n}^{0})$\\ - \textbf{for} $t=0,1,...$\\ - \>\textbf{for} $i=1,...,n$\\ - \>\>$x_{i}^{t+1}=f_{i}(x_{1}^t,...,x_i^t,...,x_{n}^t)$\\ - \>\textbf{endfor}\\ - \textbf{endfor} - \end{Algo} + $x^{0}=(x_{1}^{0},...,x_{n}^{0})$\; + \For{ $t=0,1,...$} { + \For{ $i=1,...,n$}{ + $x_{i}^{t+1}=f_{i}(x_{1}^t,...,x_i^t,...,x_{n}^t)$\; + } + } \end{algorithm} + + \noindent -to an asynchronous iterative scheme of the form: +to an asynchronous iterative scheme of the form:\\ +%% \begin{algorithm}[H] +%% \caption{Asynchronous iterative scheme}\label{algo:ch6p2async} +%% \begin{Algo} +%% $x^{0}=(x_{1}^{0},...,x_{n}^{0})$\\ +%% \textbf{for} $t=0,1,...$\\ +%% \>\textbf{for} $i=1,...,n$\\ +%% \>\>$x_{i}^{t+1}=\left\{ +%% \begin{array}[h]{ll} +%% x_i^t & \text{if } i \text{ is \emph{not} updated at iteration } i\\ +%% f_i(x_1^{s_1^i(t)},...,x_n^{s_n^i(t)}) & \text{if } i \text{ is updated at iteration } i +%% \end{array} +%% \right.$\\ +%% \>\textbf{endfor}\\ +%% \textbf{endfor} +%% \end{Algo} +%% \end{algorithm} \begin{algorithm}[H] \caption{Asynchronous iterative scheme}\label{algo:ch6p2async} - \begin{Algo} - $x^{0}=(x_{1}^{0},...,x_{n}^{0})$\\ - \textbf{for} $t=0,1,...$\\ - \>\textbf{for} $i=1,...,n$\\ - \>\>$x_{i}^{t+1}=\left\{ + $x^{0}=(x_{1}^{0},...,x_{n}^{0})$\; + \For {$t=0,1,...$} { + \For{ $i=1,...,n$} { + $x_{i}^{t+1}=\left\{ \begin{array}[h]{ll} x_i^t & \text{if } i \text{ is \emph{not} updated at iteration } i\\ f_i(x_1^{s_1^i(t)},...,x_n^{s_n^i(t)}) & \text{if } i \text{ is updated at iteration } i \end{array} - \right.$\\ - \>\textbf{endfor}\\ - \textbf{endfor} - \end{Algo} + \right.$ + } + } \end{algorithm} where $s_j^i(t)$ is the iteration number of the production of the value $x_j$ of element $j$ that is used on element $i$ at iteration $t$ (see for example~\cite{BT89,