Your first post referred to other implementation. Anyway, if you have two vectors of strings:<div><br></div><div>CPU 0: vec = [ a b c d e ]</div><div>CPU 1: vec = [ f g h i j ]</div><div><br></div><div>then all_gather will produce a vector of strings:</div>
<div><br></div><div>result = [ a b c d e f g h i j ]</div><div><br></div><div>If you have a vector&lt;vector&lt;string&gt; &gt;, then all_gather will produce vector&lt;vector&lt;string&gt; &gt; it&#39;s not possible to change this behavior.</div>
<div><br></div><div>You begin with a bidimensional vector, then you end with a bidimensional vector. I don&#39;t know if it&#39;s possible to concatenate the matrix lines with other Boost library, but the collective operations in Boost.MPI are like in the MPI 1.1 standard, nothing else.</div>
<div><br></div><div>Regards,</div><div>Jślio.</div><div><br><div class="gmail_quote">2011/5/5 Kraus Philipp <span dir="ltr">&lt;<a href="mailto:philipp.kraus@flashpixx.de">philipp.kraus@flashpixx.de</a>&gt;</span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div style="word-wrap:break-word"><br><div><div>Am 06.05.2011 um 00:24 schrieb Jślio Hoffimann:</div><div class="im"><br><blockquote type="cite">Hi Kraus,<div><br></div><div>If i understood well, it&#39;s not the case for `all_reduce`, you need `all_gather` instead:</div>
<div><br></div><div><a href="http://www.boost.org/doc/libs/1_46_1/doc/html/boost/mpi/all_gather.html" target="_blank">http://www.boost.org/doc/libs/1_46_1/doc/html/boost/mpi/all_gather.html</a></div> <div><br></div><div><a href="http://www.boost.org/doc/libs/1_46_1/doc/html/boost/mpi/all_gather.html" target="_blank"></a>The vectors has the same size?</div>
</blockquote><br></div></div><div>No, they have different sizes. I use all_gather, but I must iterate over each element in the result vector and put the elements into a new vector. I do this at the time:</div><div><br></div>
<div>std::vector&lt; std::vector&lt;std::string&gt; &gt; result;</div><div>mpi::all_gather( mpi object, vec, result);</div><div><br></div><div>std::vector&lt;std::string&gt; myvec;</div><div>foreach( result as res )</div>
<div>     myvec.push_back( foreach in res );</div><div><br></div><div>I need the loop after all_gather and my question is: Can I do the loop call into the mpi command, so that I don&#39;t have a loop after the gather?</div>
<div><br></div><div>Thx</div><div><br></div><div>Phil </div><br></div><br>_______________________________________________<br>
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