You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
psblas3/docs/html/node94.html

180 lines
5.0 KiB
HTML

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<!--Converted with LaTeX2HTML 2008 (1.71)
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>psb_init -- Initializes PSBLAS parallel environment</TITLE>
<META NAME="description" CONTENT="psb_init -- Initializes PSBLAS parallel environment">
<META NAME="keywords" CONTENT="userhtml">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">
<META NAME="Generator" CONTENT="LaTeX2HTML v2008">
<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">
<LINK REL="STYLESHEET" HREF="userhtml.css">
<LINK REL="next" HREF="node95.html">
<LINK REL="previous" HREF="node93.html">
<LINK REL="up" HREF="node93.html">
<LINK REL="next" HREF="node95.html">
</HEAD>
<BODY >
<!--Navigation Panel-->
<A NAME="tex2html1416"
HREF="node95.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A>
<A NAME="tex2html1412"
HREF="node93.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A>
<A NAME="tex2html1406"
HREF="node93.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A>
<A NAME="tex2html1414"
HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>
<BR>
<B> Next:</B> <A NAME="tex2html1417"
HREF="node95.html">psb_info Return</A>
<B> Up:</B> <A NAME="tex2html1413"
HREF="node93.html">Parallel environment routines</A>
<B> Previous:</B> <A NAME="tex2html1407"
HREF="node93.html">Parallel environment routines</A>
&nbsp; <B> <A NAME="tex2html1415"
HREF="node1.html">Contents</A></B>
<BR>
<BR>
<!--End of Navigation Panel-->
<H2><A NAME="SECTION00081000000000000000">
psb_init -- Initializes PSBLAS parallel
environment</A>
</H2>
<P>
<PRE>
call psb_init(icontxt, np, basectxt, ids)
</PRE>
<P>
This subroutine initializes the PSBLAS parallel environment, defining
a virtual parallel machine.
<DL>
<DT><STRONG>Type:</STRONG></DT>
<DD>Synchronous.
</DD>
<DT><STRONG><B>On Entry </B></STRONG></DT>
<DD>
</DD>
<DT><STRONG>np</STRONG></DT>
<DD>Number of processes in the PSBLAS virtual parallel machine.
<BR>
Scope: <B>global</B>.
<BR>
Type: <B>optional</B>.
<BR>
Intent: <B>in</B>.
<BR>
Specified as: an integer value. Default: use all available processes.
</DD>
<DT><STRONG>basectxt</STRONG></DT>
<DD>the initial communication context. The new context
will be defined from the processes participating in the initial one.
<BR>
Scope: <B>global</B>.
<BR>
Type: <B>optional</B>.
<BR>
Intent: <B>in</B>.
<BR>
Specified as: an integer value. Default: use MPI_COMM_WORLD.
</DD>
<DT><STRONG>ids</STRONG></DT>
<DD>Identities of the processes to use for the new context; the
argument is ignored when <code>np</code> is not specified. This allows the
processes in the new environment to be in an order different from the
original one.
<BR>
Scope: <B>global</B>.
<BR>
Type: <B>optional</B>.
<BR>
Intent: <B>in</B>.
<BR>
Specified as: an integer array. Default: use the indices <IMG
WIDTH="94" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
SRC="img93.png"
ALT="$(0\dots np-1)$">.
</DD>
</DL>
<P>
<DL>
<DT><STRONG><B>On Return</B></STRONG></DT>
<DD>
</DD>
<DT><STRONG>icontxt</STRONG></DT>
<DD>the communication context identifying the virtual
parallel machine. Note that this is always a duplicate of
<code>basectxt</code>, so that library communications are completely
separated from other communication operations.
<BR>
Scope: <B>global</B>.
<BR>
Type: <B>required</B>.
<BR>
Intent: <B>out</B>.
<BR>
Specified as: an integer variable.
</DD>
</DL>
<P>
<FONT SIZE="+1"><B>Notes</B></FONT>
<OL>
<LI>A call to this routine must precede any other PSBLAS call.
</LI>
<LI>It is an error to specify a value for <IMG
WIDTH="21" HEIGHT="30" ALIGN="MIDDLE" BORDER="0"
SRC="img126.png"
ALT="$np$"> greater than the
number of processes available in the underlying base parallel
environment.
</LI>
</OL>
<P>
<HR>
<!--Navigation Panel-->
<A NAME="tex2html1416"
HREF="node95.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A>
<A NAME="tex2html1412"
HREF="node93.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A>
<A NAME="tex2html1406"
HREF="node93.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A>
<A NAME="tex2html1414"
HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>
<BR>
<B> Next:</B> <A NAME="tex2html1417"
HREF="node95.html">psb_info Return</A>
<B> Up:</B> <A NAME="tex2html1413"
HREF="node93.html">Parallel environment routines</A>
<B> Previous:</B> <A NAME="tex2html1407"
HREF="node93.html">Parallel environment routines</A>
&nbsp; <B> <A NAME="tex2html1415"
HREF="node1.html">Contents</A></B>
<!--End of Navigation Panel-->
</BODY>
</HTML>