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>Module code</a> »</li> <li><a href="../../../networkx.html" accesskey="U">networkx</a> »</li> </ul> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"> <div id="searchbox" style="display: none"> <h3>Quick search</h3> <form class="search" action="../../../../search.html" method="get"> <input type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> <p class="searchtip" style="font-size: 90%"> Enter search terms or a module, class or function name. </p> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <h1>Source code for networkx.algorithms.bipartite.cluster</h1><div class="highlight"><pre> <span class="c">#-*- coding: utf-8 -*-</span> <span class="c"># Copyright (C) 2011 by </span> <span class="c"># Jordi Torrents <jtorrents@milnou.net></span> <span class="c"># Aric Hagberg <hagberg@lanl.gov></span> <span class="c"># All rights reserved.</span> <span class="c"># BSD license.</span> <span class="kn">import</span> <span class="nn">itertools</span> <span class="kn">import</span> <span class="nn">networkx</span> <span class="kn">as</span> <span class="nn">nx</span> <span class="n">__author__</span> <span class="o">=</span> <span class="s">"""</span><span class="se">\n</span><span class="s">"""</span><span class="o">.</span><span class="n">join</span><span class="p">([</span><span class="s">'Jordi Torrents <jtorrents@milnou.net>'</span><span class="p">,</span> <span class="s">'Aric Hagberg (hagberg@lanl.gov)'</span><span class="p">])</span> <span class="n">__all__</span> <span class="o">=</span> <span class="p">[</span> <span class="s">'clustering'</span><span class="p">,</span> <span class="s">'average_clustering'</span><span class="p">,</span> <span class="s">'latapy_clustering'</span><span class="p">,</span> <span class="s">'robins_alexander_clustering'</span><span class="p">]</span> <span class="c"># functions for computing clustering of pairs</span> <span class="k">def</span> <span class="nf">cc_dot</span><span class="p">(</span><span class="n">nu</span><span class="p">,</span><span class="n">nv</span><span class="p">):</span> <span class="k">return</span> <span class="nb">float</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">nu</span> <span class="o">&</span> <span class="n">nv</span><span class="p">))</span><span class="o">/</span><span class="nb">len</span><span class="p">(</span><span class="n">nu</span> <span class="o">|</span> <span class="n">nv</span><span class="p">)</span> <span class="k">def</span> <span class="nf">cc_max</span><span class="p">(</span><span class="n">nu</span><span class="p">,</span><span class="n">nv</span><span class="p">):</span> <span class="k">return</span> <span class="nb">float</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">nu</span> <span class="o">&</span> <span class="n">nv</span><span class="p">))</span><span class="o">/</span><span class="nb">max</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">nu</span><span class="p">),</span><span class="nb">len</span><span class="p">(</span><span class="n">nv</span><span class="p">))</span> <span class="k">def</span> <span class="nf">cc_min</span><span class="p">(</span><span class="n">nu</span><span class="p">,</span><span class="n">nv</span><span class="p">):</span> <span class="k">return</span> <span class="nb">float</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">nu</span> <span class="o">&</span> <span class="n">nv</span><span class="p">))</span><span class="o">/</span><span class="nb">min</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">nu</span><span class="p">),</span><span class="nb">len</span><span class="p">(</span><span class="n">nv</span><span class="p">))</span> <span class="n">modes</span><span class="o">=</span><span class="p">{</span><span class="s">'dot'</span><span class="p">:</span><span class="n">cc_dot</span><span class="p">,</span> <span class="s">'min'</span><span class="p">:</span><span class="n">cc_min</span><span class="p">,</span> <span class="s">'max'</span><span class="p">:</span><span class="n">cc_max</span><span class="p">}</span> <div class="viewcode-block" id="latapy_clustering"><a class="viewcode-back" href="../../../../reference/generated/networkx.algorithms.bipartite.cluster.latapy_clustering.html#networkx.algorithms.bipartite.cluster.latapy_clustering">[docs]</a><span class="k">def</span> <span class="nf">latapy_clustering</span><span class="p">(</span><span class="n">G</span><span class="p">,</span> <span class="n">nodes</span><span class="o">=</span><span class="bp">None</span><span class="p">,</span> <span class="n">mode</span><span class="o">=</span><span class="s">'dot'</span><span class="p">):</span> <span class="sd">r"""Compute a bipartite clustering coefficient for nodes.</span> <span class="sd"> The bipartie clustering coefficient is a measure of local density</span> <span class="sd"> of connections defined as [1]_:</span> <span class="sd"> </span> <span class="sd"> .. math::</span> <span class="sd"> c_u = \frac{\sum_{v \in N(N(v))} c_{uv} }{|N(N(u))|}</span> <span class="sd"> where `N(N(u))` are the second order neighbors of `u` in `G` excluding `u`, </span> <span class="sd"> and `c_{uv}` is the pairwise clustering coefficient between nodes </span> <span class="sd"> `u` and `v`.</span> <span class="sd"> The mode selects the function for `c_{uv}` which can be:</span> <span class="sd"> `dot`: </span> <span class="sd"> .. math::</span> <span class="sd"> c_{uv}=\frac{|N(u)\cap N(v)|}{|N(u) \cup N(v)|}</span> <span class="sd"> `min`: </span> <span class="sd"> .. math::</span> <span class="sd"> c_{uv}=\frac{|N(u)\cap N(v)|}{min(|N(u)|,|N(v)|)}</span> <span class="sd"> `max`: </span> <span class="sd"> .. math::</span> <span class="sd"> c_{uv}=\frac{|N(u)\cap N(v)|}{max(|N(u)|,|N(v)|)}</span> <span class="sd"> Parameters</span> <span class="sd"> ----------</span> <span class="sd"> G : graph</span> <span class="sd"> A bipartite graph</span> <span class="sd"> nodes : list or iterable (optional)</span> <span class="sd"> Compute bipartite clustering for these nodes. The default </span> <span class="sd"> is all nodes in G.</span> <span class="sd"> mode : string</span> <span class="sd"> The pariwise bipartite clustering method to be used in the computation.</span> <span class="sd"> It must be "dot", "max", or "min". </span> <span class="sd"> </span> <span class="sd"> Returns</span> <span class="sd"> -------</span> <span class="sd"> clustering : dictionary</span> <span class="sd"> A dictionary keyed by node with the clustering coefficient value.</span> <span class="sd"> Examples</span> <span class="sd"> --------</span> <span class="sd"> >>> from networkx.algorithms import bipartite</span> <span class="sd"> >>> G = nx.path_graph(4) # path graphs are bipartite</span> <span class="sd"> >>> c = bipartite.clustering(G) </span> <span class="sd"> >>> c[0]</span> <span class="sd"> 0.5</span> <span class="sd"> >>> c = bipartite.clustering(G,mode='min') </span> <span class="sd"> >>> c[0]</span> <span class="sd"> 1.0</span> <span class="sd"> See Also</span> <span class="sd"> --------</span> <span class="sd"> robins_alexander_clustering</span> <span class="sd"> square_clustering</span> <span class="sd"> average_clustering</span> <span class="sd"> </span> <span class="sd"> References</span> <span class="sd"> ----------</span> <span class="sd"> .. [1] Latapy, Matthieu, Clémence Magnien, and Nathalie Del Vecchio (2008).</span> <span class="sd"> Basic notions for the analysis of large two-mode networks. </span> <span class="sd"> Social Networks 30(1), 31--48.</span> <span class="sd"> """</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">nx</span><span class="o">.</span><span class="n">algorithms</span><span class="o">.</span><span class="n">bipartite</span><span class="o">.</span><span class="n">is_bipartite</span><span class="p">(</span><span class="n">G</span><span class="p">):</span> <span class="k">raise</span> <span class="n">nx</span><span class="o">.</span><span class="n">NetworkXError</span><span class="p">(</span><span class="s">"Graph is not bipartite"</span><span class="p">)</span> <span class="k">try</span><span class="p">:</span> <span class="n">cc_func</span> <span class="o">=</span> <span class="n">modes</span><span class="p">[</span><span class="n">mode</span><span class="p">]</span> <span class="k">except</span> <span class="ne">KeyError</span><span class="p">:</span> <span class="k">raise</span> <span class="n">nx</span><span class="o">.</span><span class="n">NetworkXError</span><span class="p">(</span>\ <span class="s">"Mode for bipartite clustering must be: dot, min or max"</span><span class="p">)</span> <span class="k">if</span> <span class="n">nodes</span> <span class="ow">is</span> <span class="bp">None</span><span class="p">:</span> <span class="n">nodes</span> <span class="o">=</span> <span class="n">G</span> <span class="n">ccs</span> <span class="o">=</span> <span class="p">{}</span> <span class="k">for</span> <span class="n">v</span> <span class="ow">in</span> <span class="n">nodes</span><span class="p">:</span> <span class="n">cc</span> <span class="o">=</span> <span class="mf">0.0</span> <span class="n">nbrs2</span><span class="o">=</span><span class="nb">set</span><span class="p">([</span><span class="n">u</span> <span class="k">for</span> <span class="n">nbr</span> <span class="ow">in</span> <span class="n">G</span><span class="p">[</span><span class="n">v</span><span class="p">]</span> <span class="k">for</span> <span class="n">u</span> <span class="ow">in</span> <span class="n">G</span><span class="p">[</span><span class="n">nbr</span><span class="p">]])</span><span class="o">-</span><span class="nb">set</span><span class="p">([</span><span class="n">v</span><span class="p">])</span> <span class="k">for</span> <span class="n">u</span> <span class="ow">in</span> <span class="n">nbrs2</span><span class="p">:</span> <span class="n">cc</span> <span class="o">+=</span> <span class="n">cc_func</span><span class="p">(</span><span class="nb">set</span><span class="p">(</span><span class="n">G</span><span class="p">[</span><span class="n">u</span><span class="p">]),</span><span class="nb">set</span><span class="p">(</span><span class="n">G</span><span class="p">[</span><span class="n">v</span><span class="p">]))</span> <span class="k">if</span> <span class="n">cc</span> <span class="o">></span> <span class="mf">0.0</span><span class="p">:</span> <span class="c"># len(nbrs2)>0</span> <span class="n">cc</span> <span class="o">/=</span> <span class="nb">len</span><span class="p">(</span><span class="n">nbrs2</span><span class="p">)</span> <span class="n">ccs</span><span class="p">[</span><span class="n">v</span><span class="p">]</span> <span class="o">=</span> <span class="n">cc</span> <span class="k">return</span> <span class="n">ccs</span> </div> <span class="n">clustering</span> <span class="o">=</span> <span class="n">latapy_clustering</span> <div class="viewcode-block" id="average_clustering"><a class="viewcode-back" href="../../../../reference/generated/networkx.algorithms.bipartite.cluster.average_clustering.html#networkx.algorithms.bipartite.cluster.average_clustering">[docs]</a><span class="k">def</span> <span class="nf">average_clustering</span><span class="p">(</span><span class="n">G</span><span class="p">,</span> <span class="n">nodes</span><span class="o">=</span><span class="bp">None</span><span class="p">,</span> <span class="n">mode</span><span class="o">=</span><span class="s">'dot'</span><span class="p">):</span> <span class="sd">r"""Compute the average bipartite clustering coefficient.</span> <span class="sd"> A clustering coefficient for the whole graph is the average, </span> <span class="sd"> .. math::</span> <span class="sd"> C = \frac{1}{n}\sum_{v \in G} c_v,</span> <span class="sd"> </span> <span class="sd"> where `n` is the number of nodes in `G`.</span> <span class="sd"> Similar measures for the two bipartite sets can be defined [1]_</span> <span class="sd"> </span> <span class="sd"> .. math::</span> <span class="sd"> C_X = \frac{1}{|X|}\sum_{v \in X} c_v,</span> <span class="sd"> </span> <span class="sd"> where `X` is a bipartite set of `G`.</span> <span class="sd"> Parameters</span> <span class="sd"> ----------</span> <span class="sd"> G : graph</span> <span class="sd"> a bipartite graph</span> <span class="sd"> nodes : list or iterable, optional</span> <span class="sd"> A container of nodes to use in computing the average. </span> <span class="sd"> The nodes should be either the entire graph (the default) or one of the </span> <span class="sd"> bipartite sets.</span> <span class="sd"> mode : string</span> <span class="sd"> The pariwise bipartite clustering method. </span> <span class="sd"> It must be "dot", "max", or "min" </span> <span class="sd"> </span> <span class="sd"> Returns</span> <span class="sd"> -------</span> <span class="sd"> clustering : float</span> <span class="sd"> The average bipartite clustering for the given set of nodes or the </span> <span class="sd"> entire graph if no nodes are specified.</span> <span class="sd"> Examples</span> <span class="sd"> --------</span> <span class="sd"> >>> from networkx.algorithms import bipartite</span> <span class="sd"> >>> G=nx.star_graph(3) # star graphs are bipartite</span> <span class="sd"> >>> bipartite.average_clustering(G) </span> <span class="sd"> 0.75</span> <span class="sd"> >>> X,Y=bipartite.sets(G)</span> <span class="sd"> >>> bipartite.average_clustering(G,X) </span> <span class="sd"> 0.0</span> <span class="sd"> >>> bipartite.average_clustering(G,Y) </span> <span class="sd"> 1.0</span> <span class="sd"> See Also</span> <span class="sd"> --------</span> <span class="sd"> clustering</span> <span class="sd"> </span> <span class="sd"> Notes </span> <span class="sd"> -----</span> <span class="sd"> The container of nodes passed to this function must contain all of the nodes</span> <span class="sd"> in one of the bipartite sets ("top" or "bottom") in order to compute </span> <span class="sd"> the correct average bipartite clustering coefficients.</span> <span class="sd"> References</span> <span class="sd"> ----------</span> <span class="sd"> .. [1] Latapy, Matthieu, Clémence Magnien, and Nathalie Del Vecchio (2008).</span> <span class="sd"> Basic notions for the analysis of large two-mode networks. </span> <span class="sd"> Social Networks 30(1), 31--48.</span> <span class="sd"> """</span> <span class="k">if</span> <span class="n">nodes</span> <span class="ow">is</span> <span class="bp">None</span><span class="p">:</span> <span class="n">nodes</span><span class="o">=</span><span class="n">G</span> <span class="n">ccs</span><span class="o">=</span><span class="n">latapy_clustering</span><span class="p">(</span><span class="n">G</span><span class="p">,</span> <span class="n">nodes</span><span class="o">=</span><span class="n">nodes</span><span class="p">,</span> <span class="n">mode</span><span class="o">=</span><span class="n">mode</span><span class="p">)</span> <span class="k">return</span> <span class="nb">float</span><span class="p">(</span><span class="nb">sum</span><span class="p">(</span><span class="n">ccs</span><span class="p">[</span><span class="n">v</span><span class="p">]</span> <span class="k">for</span> <span class="n">v</span> <span class="ow">in</span> <span class="n">nodes</span><span class="p">))</span><span class="o">/</span><span class="nb">len</span><span class="p">(</span><span class="n">nodes</span><span class="p">)</span> </div> <div class="viewcode-block" id="robins_alexander_clustering"><a class="viewcode-back" href="../../../../reference/generated/networkx.algorithms.bipartite.cluster.robins_alexander_clustering.html#networkx.algorithms.bipartite.cluster.robins_alexander_clustering">[docs]</a><span class="k">def</span> <span class="nf">robins_alexander_clustering</span><span class="p">(</span><span class="n">G</span><span class="p">):</span> <span class="sd">r"""Compute the bipartite clustering of G.</span> <span class="sd"> Robins and Alexander [1]_ defined bipartite clustering coefficient as</span> <span class="sd"> four times the number of four cycles `C_4` divided by the number of</span> <span class="sd"> three paths `L_3` in a bipartite graph:</span> <span class="sd"> .. math::</span> <span class="sd"> CC_4 = \frac{4 * C_4}{L_3}</span> <span class="sd"> </span> <span class="sd"> Parameters</span> <span class="sd"> ----------</span> <span class="sd"> G : graph</span> <span class="sd"> a bipartite graph</span> <span class="sd"> Returns</span> <span class="sd"> -------</span> <span class="sd"> clustering : float</span> <span class="sd"> The Robins and Alexander bipartite clustering for the input graph.</span> <span class="sd"> Examples</span> <span class="sd"> --------</span> <span class="sd"> >>> from networkx.algorithms import bipartite</span> <span class="sd"> >>> G = nx.davis_southern_women_graph()</span> <span class="sd"> >>> print(round(bipartite.robins_alexander_clustering(G), 3))</span> <span class="sd"> 0.468</span> <span class="sd"> See Also</span> <span class="sd"> --------</span> <span class="sd"> latapy_clustering</span> <span class="sd"> square_clustering</span> <span class="sd"> </span> <span class="sd"> References</span> <span class="sd"> ----------</span> <span class="sd"> .. [1] Robins, G. and M. Alexander (2004). Small worlds among interlocking </span> <span class="sd"> directors: Network structure and distance in bipartite graphs. </span> <span class="sd"> Computational & Mathematical Organization Theory 10(1), 69–94.</span> <span class="sd"> """</span> <span class="k">if</span> <span class="n">G</span><span class="o">.</span><span class="n">order</span><span class="p">()</span> <span class="o"><</span> <span class="mi">4</span> <span class="ow">or</span> <span class="n">G</span><span class="o">.</span><span class="n">size</span><span class="p">()</span> <span class="o"><</span> <span class="mi">3</span><span class="p">:</span> <span class="k">return</span> <span class="mi">0</span> <span class="n">L_3</span> <span class="o">=</span> <span class="n">_threepaths</span><span class="p">(</span><span class="n">G</span><span class="p">)</span> <span class="k">if</span> <span class="n">L_3</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span> <span class="k">return</span> <span class="mi">0</span> <span class="n">C_4</span> <span class="o">=</span> <span class="n">_four_cycles</span><span class="p">(</span><span class="n">G</span><span class="p">)</span> <span class="k">return</span> <span class="p">(</span><span class="mf">4.</span> <span class="o">*</span> <span class="n">C_4</span><span class="p">)</span> <span class="o">/</span> <span class="n">L_3</span> </div> <span class="k">def</span> <span class="nf">_four_cycles</span><span class="p">(</span><span class="n">G</span><span class="p">):</span> <span class="n">cycles</span> <span class="o">=</span> <span class="mi">0</span> <span class="k">for</span> <span class="n">v</span> <span class="ow">in</span> <span class="n">G</span><span class="p">:</span> <span class="k">for</span> <span class="n">u</span><span class="p">,</span> <span class="n">w</span> <span class="ow">in</span> <span class="n">itertools</span><span class="o">.</span><span class="n">combinations</span><span class="p">(</span><span class="n">G</span><span class="p">[</span><span class="n">v</span><span class="p">],</span> <span class="mi">2</span><span class="p">):</span> <span class="n">cycles</span> <span class="o">+=</span> <span class="nb">len</span><span class="p">((</span><span class="nb">set</span><span class="p">(</span><span class="n">G</span><span class="p">[</span><span class="n">u</span><span class="p">])</span> <span class="o">&</span> <span class="nb">set</span><span class="p">(</span><span class="n">G</span><span class="p">[</span><span class="n">w</span><span class="p">]))</span> <span class="o">-</span> <span class="nb">set</span><span class="p">([</span><span class="n">v</span><span class="p">]))</span> <span class="k">return</span> <span class="n">cycles</span> <span class="o">/</span> <span class="mi">4</span> <span class="k">def</span> <span class="nf">_threepaths</span><span class="p">(</span><span class="n">G</span><span class="p">):</span> <span class="n">paths</span> <span class="o">=</span> <span class="mi">0</span> <span class="k">for</span> <span class="n">v</span> <span class="ow">in</span> <span class="n">G</span><span class="p">:</span> <span class="k">for</span> <span class="n">u</span> <span class="ow">in</span> <span class="n">G</span><span class="p">[</span><span class="n">v</span><span class="p">]:</span> <span class="k">for</span> <span class="n">w</span> <span class="ow">in</span> <span class="nb">set</span><span class="p">(</span><span class="n">G</span><span class="p">[</span><span class="n">u</span><span class="p">])</span> <span class="o">-</span> <span class="nb">set</span><span class="p">([</span><span class="n">v</span><span class="p">]):</span> <span class="n">paths</span> <span class="o">+=</span> <span class="nb">len</span><span class="p">(</span><span class="nb">set</span><span class="p">(</span><span class="n">G</span><span class="p">[</span><span class="n">w</span><span class="p">])</span> <span class="o">-</span> <span class="nb">set</span><span class="p">([</span><span class="n">v</span><span class="p">,</span> <span class="n">u</span><span class="p">]))</span> <span class="c"># Divide by two because we count each three path twice</span> <span class="c"># one for each possible starting point</span> <span class="k">return</span> <span class="n">paths</span> <span class="o">/</span> <span class="mi">2</span> </pre></div> </div> </div> </div> <div class="clearer"></div> </div> <div class="related"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../../../../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../../../../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li><a href="http://networkx.github.com/">NetworkX Home </a> | </li> <li><a href="http://networkx.github.com/documentation.html">Documentation </a>| </li> <li><a href="http://networkx.github.com/download.html">Download </a> | </li> 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