<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Function all_to_all</title> <link rel="stylesheet" href="../../boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="../../mpi/reference.html#header.boost.mpi.collectives_hpp" title="Header <boost/mpi/collectives.hpp>"> <link rel="prev" href="all_reduce.html" title="Function all_reduce"> <link rel="next" href="broadcast.html" title="Function broadcast"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> <td align="center"><a href="../../../../index.html">Home</a></td> <td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="all_reduce.html"><img src="../../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../mpi/reference.html#header.boost.mpi.collectives_hpp"><img src="../../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="broadcast.html"><img src="../../../../doc/html/images/next.png" alt="Next"></a> </div> <div class="refentry" title="Function all_to_all"> <a name="boost.mpi.all_to_all"></a><div class="titlepage"></div> <div class="refnamediv"> <h2><span class="refentrytitle">Function all_to_all</span></h2> <p>boost::mpi::all_to_all — Send data from every process to every other process. </p> </div> <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> <div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="emphasis"><em>// In header: <<a class="link" href="../../mpi/reference.html#header.boost.mpi.collectives_hpp" title="Header <boost/mpi/collectives.hpp>">boost/mpi/collectives.hpp</a>> </em></span> <span class="bold"><strong>template</strong></span><<span class="bold"><strong>typename</strong></span> T> <span class="type"><span class="bold"><strong>void</strong></span></span> all_to_all(<span class="bold"><strong>const</strong></span> <a class="link" href="communicator.html" title="Class communicator">communicator</a> & comm, <span class="bold"><strong>const</strong></span> std::vector< T > & in_values, std::vector< T > & out_values); <span class="bold"><strong>template</strong></span><<span class="bold"><strong>typename</strong></span> T> <span class="type"><span class="bold"><strong>void</strong></span></span> all_to_all(<span class="bold"><strong>const</strong></span> <a class="link" href="communicator.html" title="Class communicator">communicator</a> & comm, <span class="bold"><strong>const</strong></span> T * in_values, T * out_values); <span class="bold"><strong>template</strong></span><<span class="bold"><strong>typename</strong></span> T> <span class="type"><span class="bold"><strong>void</strong></span></span> all_to_all(<span class="bold"><strong>const</strong></span> <a class="link" href="communicator.html" title="Class communicator">communicator</a> & comm, <span class="bold"><strong>const</strong></span> std::vector< T > & in_values, <span class="bold"><strong>int</strong></span> n, std::vector< T > & out_values); <span class="bold"><strong>template</strong></span><<span class="bold"><strong>typename</strong></span> T> <span class="type"><span class="bold"><strong>void</strong></span></span> all_to_all(<span class="bold"><strong>const</strong></span> <a class="link" href="communicator.html" title="Class communicator">communicator</a> & comm, <span class="bold"><strong>const</strong></span> T * in_values, <span class="bold"><strong>int</strong></span> n, T * out_values);</pre></div> <div class="refsect1" title="Description"> <a name="id1390583"></a><h2>Description</h2> <p><code class="computeroutput">all_to_all</code> is a collective algorithm that transmits <code class="computeroutput">p</code> values from every process to every other process. On process i, jth value of the <code class="computeroutput">in_values</code> vector is sent to process j and placed in the ith position of the <code class="computeroutput">out_values</code> vector in process <code class="computeroutput">j</code>. The type <code class="computeroutput">T</code> of the values may be any type that is serializable or has an associated MPI data type. If <code class="computeroutput">n</code> is provided, then arrays of <code class="computeroutput">n</code> values will be transferred from one process to another.</p> <p>When the type <code class="computeroutput">T</code> has an associated MPI data type, this routine invokes <code class="computeroutput">MPI_Alltoall</code> to scatter the values.</p> <p> </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody><tr> <td><p><span class="term">Parameters:</span></p></td> <td><div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><code class="computeroutput">comm</code></span></p></td> <td><p>The communicator over which the all-to-all communication will occur.</p></td> </tr> <tr> <td><p><span class="term"><code class="computeroutput">in_values</code></span></p></td> <td><p>A vector or pointer to storage that contains the values to send to each process, indexed by the process ID number.</p></td> </tr> <tr> <td><p><span class="term"><code class="computeroutput">out_values</code></span></p></td> <td><p>A vector or pointer to storage that will be updated to contain the values received from other processes. The jth value in <code class="computeroutput">out_values</code> will come from the procss with rank j. </p></td> </tr> </tbody> </table></div></td> </tr></tbody> </table></div> </div> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> <td align="right"><div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor, Matthias Troyer, Trustees of Indiana University<p> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top"> http://www.boost.org/LICENSE_1_0.txt </a>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="all_reduce.html"><img src="../../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../mpi/reference.html#header.boost.mpi.collectives_hpp"><img src="../../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="broadcast.html"><img src="../../../../doc/html/images/next.png" alt="Next"></a> </div> </body> </html>