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https://issues.apache.org/jira/browse/FLINK-5311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15741437#comment-15741437
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ASF GitHub Bot commented on FLINK-5311:
---------------------------------------
Github user vasia commented on a diff in the pull request:
https://github.com/apache/flink/pull/2984#discussion_r91908589
--- Diff: docs/dev/libs/gelly/bipartite_graph.md ---
@@ -0,0 +1,148 @@
+---
+title: Graph Generators
+nav-parent_id: graphs
+nav-pos: 6
+---
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements. See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership. The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied. See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+* This will be replaced by the TOC
+{:toc}
+
+Bipartite Graph
+---------------
+
+A bipartite graph (also called a two-mode graph) is a type of graph where
vertices are separated into two disjoint sets. These sets are usually called
top and bottom vertices. A single edge in this graph can only connect vertices
from opposite sets (i.e. bottom vertex to top vertex) and cannot connect to
vertices in the same set.
+
+Theses graphs have wide application in practice and can be a more natural
choice for particular domains. For example to represent authorship of
scientific papers top vertices can represent scientific papers while bottom
nodes will represent authors. Naturally a node between a top and a bottom nodes
would represent an authorship of a particular scientific paper. Another common
example for applications of bipartite graphs is a relationships between actors
and movies. In this case an edge represents that a particular actor played in a
movie.
+
+Bipartite graph are used instead of regular graphs (one-mode) for the
following practical
[reasons](http://www.complexnetworks.fr/wp-content/uploads/2011/01/socnet07.pdf):
+ * They preserve more information about a connection between vertices. For
example instead of a single link between two researchers in a graph that
represents that they authored a paper together a bipartite graph preserve the
information about what papers they authored
+ * Bipartite graph can encode the same information more compactly than
one-mode graphs
+
+
+
+Graph Representation
+--------------------
+
+A `BipartiteGraph` is represented by:
+ * `DataSet` of top nodes
+ * `DataSet` of bottom nodes
+ * `DataSet` of edges between top and bottom nodes
+
+As in the `Graph` class nodes are represented by the `Vertex` type and the
same rules applies to its types and values.
+
+The graph edges are represented by the `BipartiteEdge` type. An
`BipartiteEdge` is defined by a top ID (the ID of the top `Vertex`), a bottom
ID (the ID of the bottom `Vertex`) and an optional value. The main difference
between the `Edge` and `BipartiteEdge` is that IDs of nodes it links can be of
different types. Edges with no value have a `NullValue` value type.
+
+<div class="codetabs" markdown="1">
+<div data-lang="java" markdown="1">
+{% highlight java %}
+BipartiteEdge<Long, String, Double> e = new BipartiteEdge<Long, String,
Double>(1L, "id1", 0.5);
+
+Double weight = e.getValue(); // weight = 0.5
+{% endhighlight %}
+</div>
+
+<div data-lang="scala" markdown="1">
+{% highlight scala %}
+// TODO: Should be added when Scala interface is implemented
+{% endhighlight %}
+</div>
+</div>
+{% top %}
+
+
+Graph Creation
+--------------
+
+You can create a `BipartiteGraph` in the following ways:
+
+* from a `DataSet` of top vertices, a `DataSet` of bottom vertices and a
`DataSet` of edges:
+
+<div class="codetabs" markdown="1">
+<div data-lang="java" markdown="1">
+{% highlight java %}
+ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
+
+DataSet<Vertex<String, Long>> topVertices = ...
+
+DataSet<Vertex<String, Long>> bottomVertices = ...
+
+DataSet<Edge<String, String, Double>> edges = ...
+
+Graph<String, String, Long, Long, Double> graph =
BipartiteGraph.fromDataSet(topVertices, bottomVertices, edges, env);
+{% endhighlight %}
+</div>
+
+<div data-lang="scala" markdown="1">
+{% highlight scala %}
+// TODO: Should be added when Scala interface is implemented
--- End diff --
same as above
> Write user documentation for BipartiteGraph
> -------------------------------------------
>
> Key: FLINK-5311
> URL: https://issues.apache.org/jira/browse/FLINK-5311
> Project: Flink
> Issue Type: Bug
> Components: Gelly
> Reporter: Ivan Mushketyk
> Assignee: Ivan Mushketyk
>
> We need to add user documentation. The progress on BipartiteGraph can be
> tracked in the following JIRA:
> https://issues.apache.org/jira/browse/FLINK-2254
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