<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 2012 (1.2) original version by: Nikos Drakos, CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>User-defined index mappings</TITLE> <META NAME="description" CONTENT="User-defined index mappings"> <META NAME="keywords" CONTENT="userhtml"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META NAME="Generator" CONTENT="LaTeX2HTML v2012"> <META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"> <LINK REL="STYLESHEET" HREF="userhtml.css"> <LINK REL="previous" HREF="node6.html"> <LINK REL="up" HREF="node6.html"> <LINK REL="next" HREF="node8.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html271" HREF="node8.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html267" HREF="node6.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html263" HREF="node6.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html269" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <BR> <B> Next:</B> <A NAME="tex2html272" HREF="node8.html">Programming model</A> <B> Up:</B> <A NAME="tex2html268" HREF="node6.html">Application structure</A> <B> Previous:</B> <A NAME="tex2html264" HREF="node6.html">Application structure</A> <B> <A NAME="tex2html270" HREF="node1.html">Contents</A></B> <BR> <BR> <!--End of Navigation Panel--> <H3><A NAME="SECTION00033100000000000000"></A> <A NAME="sec:usermaps"></A> <BR> User-defined index mappings </H3> PSBLAS supports user-defined global to local index mappings, subject to the constraints outlined in sec. <A HREF="node6.html#sec:appstruct">2.3</A>: <OL> <LI>The set of indices owned locally must be mapped to the set <!-- MATH $1\dots n_{\hbox{row}_i}$ --> <IMG WIDTH="77" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img17.png" ALT="$1\dots n_{\hbox{row}_i}$">; </LI> <LI>The set of halo points must be mapped to the set <!-- MATH $n_{\hbox{row}_i}+1\dots n_{\hbox{col}_i}$ --> <IMG WIDTH="130" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img18.png" ALT="$n_{\hbox{row}_i}+1\dots n_{\hbox{col}_i}$">; </LI> </OL> but otherwise the mapping is arbitrary. The user application is responsible to ensure consistency of this mapping; some errors may be caught by the library, but this is not guaranteed. The application structure to support this usage is as follows: <OL> <LI>Initialize index space with <code>psb_cdall(ictx,desc,info,vl=vl,lidx=lidx)</code> passing the vectors <code>vl(:)</code> containing the set of global indices owned by the current process and <code>lidx(:)</code> containing the corresponding local indices; </LI> <LI>Add the halo points <code>ja(:)</code> and their associated local indices <code>lidx(:)</code> with a(some) call(s) to <code>psb_cdins(nz,ja,desc,info,lidx=lidx)</code>; </LI> <LI>Assemble the descriptor with <code>psb_cdasb</code>; </LI> <LI>Build the sparse matrices and vectors, optionally making use in <code>psb_spins</code> and <code>psb_geins</code> of the <code>local</code> argument specifying that the indices in <code>ia</code>, <code>ja</code> and <code>irw</code>, respectively, are already local indices. </LI> </OL> <P> <BR><HR> </BODY> </HTML>