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<div class="section" id="chordal-graph-treewidth">
<h1>chordal_graph_treewidth<a class="headerlink" href="#chordal-graph-treewidth" title="Permalink to this headline">¶</a></h1>
<dl class="function">
<dt id="networkx.algorithms.chordal.chordal_alg.chordal_graph_treewidth">
<tt class="descname">chordal_graph_treewidth</tt><big>(</big><em>G</em><big>)</big><a class="reference internal" href="../../_modules/networkx/algorithms/chordal/chordal_alg.html#chordal_graph_treewidth"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#networkx.algorithms.chordal.chordal_alg.chordal_graph_treewidth" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the treewidth of the chordal graph G.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters :</th><td class="field-body"><p class="first"><strong>G</strong> : graph</p>
<blockquote>
<div><p>A NetworkX graph</p>
</div></blockquote>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns :</th><td class="field-body"><p class="first"><strong>treewidth</strong> : int</p>
<blockquote>
<div><p>The size of the largest clique in the graph minus one.</p>
</div></blockquote>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Raises :</th><td class="field-body"><p class="first"><strong>NetworkXError</strong> :</p>
<blockquote class="last">
<div><p>The algorithm does not support DiGraph, MultiGraph and MultiDiGraph.
If the input graph is an instance of one of these classes, a
NetworkXError is raised.
The algorithm can only be applied to chordal graphs. If
the input graph is found to be non-chordal, a NetworkXError is raised.</p>
</div></blockquote>
</td>
</tr>
</tbody>
</table>
<p class="rubric">References</p>
<table class="docutils citation" frame="void" id="r177" rules="none">
<colgroup><col class="label" /><col /></colgroup>
<tbody valign="top">
<tr><td class="label"><a class="fn-backref" href="#id1">[R177]</a></td><td><a class="reference external" href="http://en.wikipedia.org/wiki/Tree_decomposition#Treewidth">http://en.wikipedia.org/wiki/Tree_decomposition#Treewidth</a></td></tr>
</tbody>
</table>
<p class="rubric">Examples</p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">networkx</span> <span class="kn">as</span> <span class="nn">nx</span>
<span class="gp">>>> </span><span class="n">e</span> <span class="o">=</span> <span class="p">[(</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">),(</span><span class="mi">1</span><span class="p">,</span><span class="mi">3</span><span class="p">),(</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">),(</span><span class="mi">2</span><span class="p">,</span><span class="mi">4</span><span class="p">),(</span><span class="mi">3</span><span class="p">,</span><span class="mi">4</span><span class="p">),(</span><span class="mi">3</span><span class="p">,</span><span class="mi">5</span><span class="p">),(</span><span class="mi">3</span><span class="p">,</span><span class="mi">6</span><span class="p">),(</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">),(</span><span class="mi">4</span><span class="p">,</span><span class="mi">6</span><span class="p">),(</span><span class="mi">5</span><span class="p">,</span><span class="mi">6</span><span class="p">),(</span><span class="mi">7</span><span class="p">,</span><span class="mi">8</span><span class="p">)]</span>
<span class="gp">>>> </span><span class="n">G</span> <span class="o">=</span> <span class="n">nx</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="n">e</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">G</span><span class="o">.</span><span class="n">add_node</span><span class="p">(</span><span class="mi">9</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">nx</span><span class="o">.</span><span class="n">chordal_graph_treewidth</span><span class="p">(</span><span class="n">G</span><span class="p">)</span>
<span class="go">3</span>
</pre></div>
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