MaplePrimes - Questions and Posts tagged with graphtheory
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en-us2017 Maplesoft, A Division of Waterloo Maple Inc.Maplesoft Document SystemMon, 27 Feb 2017 15:48:59 GMTMon, 27 Feb 2017 15:48:59 GMTThe most recent questions and posts on MaplePrimes tagged with graphtheoryhttp://www.mapleprimes.com/images/mapleprimeswhite.jpgMaplePrimes - Questions and Posts tagged with graphtheory
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Vertex Weight graph theory
http://www.mapleprimes.com/questions/221211-Vertex-Weight-Graph-Theory?ref=Feed:MaplePrimes:Tagged With graphtheory
<p>how to define VertexWeight in Graph Theory package</p>
<p>how to define VertexWeight in Graph Theory package</p>
221211Thu, 16 Feb 2017 15:33:21 ZhakanhakanSearch for an explanation about CycleBasis
http://www.mapleprimes.com/questions/216126-Search-For-An-Explanation-About-CycleBasis?ref=Feed:MaplePrimes:Tagged With graphtheory
<p>Could someone please explain to me why the procedure GraphTheory:-CycleBasis requires that the vertices of a graph be integers for it to work correctly ?<br>(while the definition of a graph supports other types of vertex names)<br><br><br>restart:<br>with(GraphTheory):<br><br>#------------------------------------------------------- test 1<br><br>g1 := Graph({{"a", 1}, {1, 3}, {"a", 3}});<br>DrawGraph(g1);<br>CycleBasis(g1);</p>
<p>Error, (in GraphTheory:-CycleBasis) cannot determine if this expression is true or false: "a" < 1<br><br></p>
<p>#------------------------------------------------------- test 2<br><br>g2 := Graph({{a, 1}, {1, 3}, {a, 3}});<br>CycleBasis(g2);</p>
<p>Error, (in GraphTheory:-CycleBasis) cannot determine if this expression is true or false: a < 1</p>
<p> </p>
<p><strong>#------------------------------------------------------- test 3</strong><br><br><strong>g3 := Graph({{4, 1}, {1, 3}, {4, 3}});</strong><br><strong>CycleBasis(g3);</strong></p>
<p><strong>[[1, 3, 4]]</strong></p>
<p> <br><em>Knowing this limitation I usually rename to integers the vertices of the graphs, next do some operations, and next go back to the original names.</em><br><br><br>Thanks for any explanation.</p><p>Could someone please explain to me why the procedure GraphTheory:-CycleBasis requires that the vertices of a graph be integers for it to work correctly ?<br>(while the definition of a graph supports other types of vertex names)<br><br><br>restart:<br>with(GraphTheory):<br><br>#------------------------------------------------------- test 1<br><br>g1 := Graph({{"a", 1}, {1, 3}, {"a", 3}});<br>DrawGraph(g1);<br>CycleBasis(g1);</p>
<p>Error, (in GraphTheory:-CycleBasis) cannot determine if this expression is true or false: "a" < 1<br><br></p>
<p>#------------------------------------------------------- test 2<br><br>g2 := Graph({{a, 1}, {1, 3}, {a, 3}});<br>CycleBasis(g2);</p>
<p>Error, (in GraphTheory:-CycleBasis) cannot determine if this expression is true or false: a < 1</p>
<p> </p>
<p><strong>#------------------------------------------------------- test 3</strong><br><br><strong>g3 := Graph({{4, 1}, {1, 3}, {4, 3}});</strong><br><strong>CycleBasis(g3);</strong></p>
<p><strong>[[1, 3, 4]]</strong></p>
<p> <br><em>Knowing this limitation I usually rename to integers the vertices of the graphs, next do some operations, and next go back to the original names.</em><br><br><br>Thanks for any explanation.</p>216126Wed, 17 Aug 2016 08:14:47 ZmmcdarammcdaraHow to export undirected graph to C#?
http://www.mapleprimes.com/questions/212765-How-To-Export-Undirected-Graph-To-C?ref=Feed:MaplePrimes:Tagged With graphtheory
<p>Hi all,</p>
<p>I drew a undirected graph using Maple</p>
<p>restart;<br>with(GraphTheory);<br>with(SpecialGraphs);<br>with(RandomGraphs);<br>G := Graph(undirected, {[{1, 2}, 4], {1, 4}, {2, 3}, {2, 5}, {3, 4}});<br>DrawGraph(G, style = circle);<br><br></p>
<p>I want to import this graph to picturebox or panel on C#, please help me!</p><p>Hi all,</p>
<p>I drew a undirected graph using Maple</p>
<p>restart;<br>with(GraphTheory);<br>with(SpecialGraphs);<br>with(RandomGraphs);<br>G := Graph(undirected, {[{1, 2}, 4], {1, 4}, {2, 3}, {2, 5}, {3, 4}});<br>DrawGraph(G, style = circle);<br><br></p>
<p>I want to import this graph to picturebox or panel on C#, please help me!</p>212765Thu, 26 May 2016 11:01:10 ZlongqnhlongqnhHow to simulate random walks on graphs?
http://www.mapleprimes.com/questions/212505-How-To-Simulate-Random-Walks-On-Graphs?ref=Feed:MaplePrimes:Tagged With graphtheory
<p>This week I am participating in <a href="http://www.icmp.lviv.ua/ising/ising2016.html">19th Ising lectures</a> (see <a href="https://drive.google.com/folderview?id=0B0uPwoK-03XgSEZpYWljYnpXN0U&usp=sharing">https://drive.google.com/folderview?id=0B0uPwoK-03XgSEZpYWljYnpXN0U&usp=sharing</a>). The Serguei Nechaev's talk inspired me to ask the question: <br>"How to simulate a random walk on an undirected and unweighted (and, of course, connected) graph <br>(All the paths from a vertex of degree k have the same probability 1/k.)?"<br>A Maple procedure to this end is welcome.</p><p>This week I am participating in <a href="http://www.icmp.lviv.ua/ising/ising2016.html">19th Ising lectures</a> (see <a href="https://drive.google.com/folderview?id=0B0uPwoK-03XgSEZpYWljYnpXN0U&usp=sharing">https://drive.google.com/folderview?id=0B0uPwoK-03XgSEZpYWljYnpXN0U&usp=sharing</a>). The Serguei Nechaev's talk inspired me to ask the question: <br>"How to simulate a random walk on an undirected and unweighted (and, of course, connected) graph <br>(All the paths from a vertex of degree k have the same probability 1/k.)?"<br>A Maple procedure to this end is welcome.</p>212505Wed, 18 May 2016 16:13:33 ZMarkiyan HirnykMarkiyan HirnykApproximate solution of Traveling Salesman Problem
http://www.mapleprimes.com/questions/210365-Approximate-Solution-Of-Traveling-Salesman?ref=Feed:MaplePrimes:Tagged With graphtheory
<p>I am looking for a quick implementation in Maple to approximate a solution to the travelling salesman problem in a graph of several thousand vertices randomly placed in the unit square. I've tried TravelingSaleman in the GraphTheory package; it bogs down with just a handful (say, twelve) of vertices. I also tried Bruno Buerrier's <a href="http://www.maplesoft.com/applications/view.aspx?SID=6873&view=html">implementation</a> of the two-opt algorithm; on my machine that took more than a day for 2048 vertices. </p>
<p>Is anyone aware of a quicker implementation in Maple?</p><p>I am looking for a quick implementation in Maple to approximate a solution to the travelling salesman problem in a graph of several thousand vertices randomly placed in the unit square. I've tried TravelingSaleman in the GraphTheory package; it bogs down with just a handful (say, twelve) of vertices. I also tried Bruno Buerrier's <a href="http://www.maplesoft.com/applications/view.aspx?SID=6873&view=html">implementation</a> of the two-opt algorithm; on my machine that took more than a day for 2048 vertices. </p>
<p>Is anyone aware of a quicker implementation in Maple?</p>210365Tue, 15 Mar 2016 18:25:40 ZKonigsberg Graph?
http://www.mapleprimes.com/questions/209702-Konigsberg-Graph?ref=Feed:MaplePrimes:Tagged With graphtheory
<p>Hello I'm having trouble create Konigsberg Graph on Maple. Here's the picture. Sorry if it's not clear enough. Thanks!</p>
<p> </p>
<p>https://www.google.co.id/url?sa=i&source=images&cd=&ved=&url=https%3A%2F%2Fmvngu.wordpress.com%2F2011%2F03%2F26%2Fsimple-graphs-bridges-of-konigsberg-and-directed-graphs%2F&psig=AFQjCNFP-tdRTqi-VapOJZ-TLPdA1ndSgQ&ust=1456326114883065&rct=j</p><p>Hello I'm having trouble create Konigsberg Graph on Maple. Here's the picture. Sorry if it's not clear enough. Thanks!</p>
<p> </p>
<p>https://www.google.co.id/url?sa=i&source=images&cd=&ved=&url=https%3A%2F%2Fmvngu.wordpress.com%2F2011%2F03%2F26%2Fsimple-graphs-bridges-of-konigsberg-and-directed-graphs%2F&psig=AFQjCNFP-tdRTqi-VapOJZ-TLPdA1ndSgQ&ust=1456326114883065&rct=j</p>209702Tue, 23 Feb 2016 15:06:52 ZKimkimkimKimkimkim