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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Will look at the RcppEigen package. For other purposes I already use the RBGL package which interfaces the boost graph library. However, the interface
goes via S4 type methods – so everything is slow… ;)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Regards<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Søren<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext"> Glenn Lawyer [mailto:lawyer@mpi-inf.mpg.de]
<br>
<b>Sent:</b> 24. juni 2012 19:56<br>
<b>To:</b> Søren Højsgaard<br>
<b>Cc:</b> rcpp-devel@lists.r-forge.r-project.org (rcpp-devel@r-forge.wu-wien.ac.at)<br>
<b>Subject:</b> Re: [Rcpp-devel] Using sparse matrices from the Matrix package in Rcpp<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I would suggest using the eigen library, Rccp has an interface to this. Alternately, you could link to the boost graph library.<br>
<br>
+glenn<br>
<br>
On 06/24/2012 06:12 PM, Søren Højsgaard wrote: <o:p></o:p></p>
<pre>Dear list<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>I have code for graph operations where I represent graphs as adjacency matrices (matrices with 0's and 1's). When graphs grow large storing all the 0's becomes uneconomical, so I want to use sparse matrices (from the Matrix package) for large graphs instead. Simple indexing operations like M[i,j] however are very slow, so I wonder if there are ways of dealing with sparse matrices (and rapid indexing) in the Rcpp framework. Apologies if I have overlooked posts on this topic.<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Regards<o:p></o:p></pre>
<pre>Søren<o:p></o:p></pre>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>Rcpp-devel mailing list<o:p></o:p></pre>
<pre><a href="mailto:Rcpp-devel@lists.r-forge.r-project.org">Rcpp-devel@lists.r-forge.r-project.org</a><o:p></o:p></pre>
<pre><a href="https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel">https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel</a><o:p></o:p></pre>
<p class="MsoNormal"><br>
<br>
<o:p></o:p></p>
<pre>-- <o:p></o:p></pre>
<pre>-----------------------------------<o:p></o:p></pre>
<pre>It is difficult to find a black cat in a dark room,<o:p></o:p></pre>
<pre>especially if there is no cat.<o:p></o:p></pre>
<pre> -- Chinese proverb<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre> Dr. Glenn Lawyer <o:p></o:p></pre>
<pre> +352 661 967 244 <o:p></o:p></pre>
<pre> Max-Planck-Institut für Informatik<o:p></o:p></pre>
<pre> Computational Biology and Applied Algorithmics<o:p></o:p></pre>
<pre> Campus E1 4<o:p></o:p></pre>
<pre> 66123 Saarbrücken, Germany<o:p></o:p></pre>
<pre> <a href="http://bioinf.mpi-inf.mpg.de/~lawyer">http://bioinf.mpi-inf.mpg.de/~lawyer</a><o:p></o:p></pre>
<pre><o:p> </o:p></pre>
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