X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/kahina_paper1.git/blobdiff_plain/4bba0524dc08c15ba13863012d6bc90480c18721..6f76482b569516829ba1ec3f0358dec6c479c001:/paper.tex diff --git a/paper.tex b/paper.tex index c8a6698..9897244 100644 --- a/paper.tex +++ b/paper.tex @@ -96,7 +96,7 @@ root finding of polynomials, high degree, iterative methods, Durant-Kerner, GPU, Polynomials are algebraic structures used in mathematics that capture physical phenomenons and that express the outcome in the form of a function of some unknown variable. Formally speaking, a polynomial $p(x)$ of degree \textit{n} having $n$ coefficients in the complex plane \textit{C} and zeros $\alpha_{i},\textit{i=1,...,n}$ %%\begin{center} \begin{equation} - {\Large p(x)=\sum{a_{i}x^{i}}=a_{n}\prod(x-\alpha_{i}),a_{0} a_{n}\neq 0}. + {\Large p(x)=\sum_{i=0}^{n}{a_{i}x^{i}}=a_{n}\prod_{i=1}^{n}(x-\alpha_{i}), a_{0} a_{n}\neq 0}. \end{equation} %%\end{center} @@ -583,33 +583,27 @@ or from GPU memory to CPU memory \verb=(cudaMemcpyDeviceToHost))=. \section{Experimental study} \subsection{Definition of the polynomial used} -We use two forms of polynomials: -\paragraph{sparse polynomial}: -in this following form, the roots are distributed on 2 distinct circles: +We study two forms of polynomials the sparse polynomials and the full polynomials: +\paragraph{Sparse polynomial}: in this following form, the roots are distributed on 2 distinct circles: \begin{equation} - \forall \alpha_{1} \alpha_{2} \in C,\forall n_{1},n_{2} \in N^{*}; P(z)= (z^{n^{1}}-\alpha_{1})(z^{n^{2}}-\alpha_{2}) + \forall \alpha_{1} \alpha_{2} \in C,\forall n_{1},n_{2} \in N^{*}; P(z)= (z^{n_{1}}-\alpha_{1})(z^{n_{2}}-\alpha_{2}) \end{equation} This form makes it possible to associate roots having two different modules and thus to work on a polynomial constitute of four non zero terms. -\paragraph{Full polynomial}: - the second form used to obtain a full polynomial is: +\paragraph{Full polynomial}: the second form used to obtain a full polynomial is: %%\begin{equation} %%\forall \alpha_{i} \in C,\forall n_{i}\in N^{*}; P(z)= \sum^{n}_{i=1}(z^{n^{i}}.a_{i}) %%\end{equation} \begin{equation} - {\Large \forall a_{i} \in C, i\in N; p(x)=\sum^{n-1}_{i=1} a_{i}.x^{i}} + {\Large \forall a_{i} \in C, i\in N; p(x)=\sum^{n}_{i=0} a_{i}.x^{i}} \end{equation} with this form, we can have until \textit{n} non zero terms. \subsection{The study condition} -In order to have representative average values, for each -point of our curves we measured the roots finding of 10 -different polynomials. - The our experiences results concern two parameters which are the polynomial degree and the execution time of our program to converge on the solution. The polynomial degree allows us @@ -617,7 +611,7 @@ to validate that our algorithm is powerful with high degree polynomials. The execution time remains the element-key which justifies our work of parallelization. For our tests we used a CPU Intel(R) Xeon(R) CPU -E5620@2.40GHz and a GPU K40 (with 6 Go of ram) +E5620@2.40GHz and a GPU K40 (with 6 Go of ram). \subsection{Comparative study} @@ -678,7 +672,12 @@ We initially carried out the convergence of Aberth algorithm with various sizes \label{fig:01} \end{figure} - +\begin{figure}[htbp] +\centering + \includegraphics[width=0.8\textwidth]{figures/log_exp} +\caption{The impact of exp-log solution to compute very high degrees of polynomial.} +\label{fig:01} +\end{figure} \subsubsection{A comparative study between Aberth and Durand-kerner algorithm} \begin{table}[htbp]