<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html > <head><title>Abstract</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <meta name="generator" content="TeX4ht (http://www.tug.org/tex4ht/)"> <meta name="originator" content="TeX4ht (http://www.tug.org/tex4ht/)"> <!-- html,3 --> <meta name="src" content="userhtml.tex"> <link rel="stylesheet" type="text/css" href="userhtml.css"> </head><body > <!--l. 1--><div class="crosslinks"><p class="noindent"><span class="cmr-12">[</span><a href="userhtmlli2.html" ><span class="cmr-12">next</span></a><span class="cmr-12">] [</span><a href="#tailuserhtmlli1.html"><span class="cmr-12">tail</span></a><span class="cmr-12">] [</span><a href="userhtml.html#userhtmlli1.html" ><span class="cmr-12">up</span></a><span class="cmr-12">] </span></p></div> <h3 class="likesectionHead"><a id="x2-1000"></a><span class="cmr-12">Abstract</span></h3> <a id="Q1-2-2"></a> <!--l. 5--><p class="noindent" ><span class="cmcsc-10x-x-120">MLD2P4 (M<span class="small-caps">u</span><span class="small-caps">l</span><span class="small-caps">t</span><span class="small-caps">i</span>L<span class="small-caps">e</span><span class="small-caps">v</span><span class="small-caps">e</span><span class="small-caps">l</span> D<span class="small-caps">o</span><span class="small-caps">m</span><span class="small-caps">a</span><span class="small-caps">i</span><span class="small-caps">n</span> D<span class="small-caps">e</span><span class="small-caps">c</span><span class="small-caps">o</span><span class="small-caps">m</span><span class="small-caps">p</span><span class="small-caps">o</span><span class="small-caps">s</span><span class="small-caps">i</span><span class="small-caps">t</span><span class="small-caps">i</span><span class="small-caps">o</span><span class="small-caps">n</span> P<span class="small-caps">a</span><span class="small-caps">r</span><span class="small-caps">a</span><span class="small-caps">l</span><span class="small-caps">l</span><span class="small-caps">e</span><span class="small-caps">l</span> P<span class="small-caps">r</span><span class="small-caps">e</span><span class="small-caps">c</span><span class="small-caps">o</span><span class="small-caps">n</span><span class="small-caps">d</span><span class="small-caps">i</span><span class="small-caps">t</span><span class="small-caps">i</span><span class="small-caps">o</span><span class="small-caps">n</span><span class="small-caps">e</span><span class="small-caps">r</span><span class="small-caps">s</span></span> <span class="cmcsc-10x-x-120">P<span class="small-caps">a</span><span class="small-caps">c</span><span class="small-caps">k</span><span class="small-caps">a</span><span class="small-caps">g</span><span class="small-caps">e</span> <span class="small-caps">b</span><span class="small-caps">a</span><span class="small-caps">s</span><span class="small-caps">e</span><span class="small-caps">d</span> <span class="small-caps">o</span><span class="small-caps">n</span> PSBLAS</span><span class="cmr-12">) is a package of parallel algebraic multilevel</span> <span class="cmr-12">preconditioners. The first release of MLD2P4 made available multilevel additive and</span> <span class="cmr-12">hybrid Schwarz preconditioners, as well as one-level additive Schwarz preconditioners.</span> <span class="cmr-12">The package has been extended to include further multilevel cycles and smoothers</span> <span class="cmr-12">widely used in multigrid methods. In the multilevel case, a purely algebraic approach is</span> <span class="cmr-12">applied to generate coarse-level corrections, so that no geometric background is needed</span> <span class="cmr-12">concerning the matrix to be preconditioned. The matrix is assumed to be square, real</span> <span class="cmr-12">or complex.</span> <!--l. 14--><p class="indent" > <span class="cmr-12">MLD2P4 has been designed to provide scalable and easy-to-use preconditioners in</span> <span class="cmr-12">the context of the PSBLAS (Parallel Sparse Basic Linear Algebra Subprograms)</span> <span class="cmr-12">computational framework and can be used in conjuction with the Krylov solvers</span> <span class="cmr-12">available in this framework. MLD2P4 enables the user to easily specify different</span> <span class="cmr-12">features of an algebraic multilevel preconditioner, thus allowing to search for the “best”</span> <span class="cmr-12">preconditioner for the problem at hand.</span> <!--l. 21--><p class="indent" > <span class="cmr-12">The package employs object-oriented design techniques in Fortran</span><span class="cmr-12"> 2003, with</span> <span class="cmr-12">interfaces to additional third party libraries such as MUMPS, UMFPACK, SuperLU,</span> <span class="cmr-12">and SuperLU</span><span class="cmr-12">_Dist, which can be exploited in building multilevel preconditioners. The</span> <span class="cmr-12">parallel implementation is based on a Single Program Multiple Data (SPMD)</span> <span class="cmr-12">paradigm; the inter-process communication is based on MPI and is managed mainly</span> <span class="cmr-12">through PSBLAS.</span> <!--l. 29--><p class="indent" > <span class="cmr-12">This guide provides a brief description of the functionalities and the user interface</span> <span class="cmr-12">of MLD2P4.</span> <!--l. 123--><div class="crosslinks"><p class="noindent"><span class="cmr-12">[</span><a href="userhtmlli2.html" ><span class="cmr-12">next</span></a><span class="cmr-12">] [</span><a href="userhtmlli1.html" ><span class="cmr-12">front</span></a><span class="cmr-12">] [</span><a href="userhtml.html#userhtmlli1.html" ><span class="cmr-12">up</span></a><span class="cmr-12">] </span></p></div> <!--l. 123--><p class="indent" > <a id="tailuserhtmlli1.html"></a> </body></html>