Connectors

An R package to build GEXF graph files

rgexf is an R package that allows to work with GEXF format graph files (XML) reading and writing GEXF files. Its main function, write.gexf, builds gexf files which as basic arguments requires two data.frames, a nodes matrix and a edges matrix. In addition it currently supports networks dynamics such as start and end attributes (for both, nodes and edges) and spells, including attributes and viz attributes (link). Current version is rgexf v0.14.3 (march 11, 2014) and its available in The Comprehensive R Archive Network (CRAN). link.

See the gephi post.

Exporting R data to GEXF graph files (some examples)

write.gexf() is a function that as basic arguments requires two matrices, a nodes matrix and a edges matrix, both character matrix. In addition it currently supports dynamics nodes/edges and attributes for nodes/edges.

Example 1: Static net

Creating a group of individuals and their relations

> people <- matrix(c(1:4, 'juan', 'pedro', 'matthew', 'carlos'),ncol=2)
> people
    [,1] [,2]    
[1,] "1"  "juan"  
[2,] "2"  "pedro" 
[3,] "3"  "matthew"
[4,] "4"  "carlos"

Defining the relations structure

> relations <- matrix(c(1,4,1,2,1,3,2,3,3,4,4,2), ncol=2, byrow=T)
    [,1] [,2]
[1,]    1    4
[2,]    1    2
[3,]    1    3
[4,]    2    3
[5,]    3    4
[6,]    4    2

Getting things done

> write.gexf(people, relations)

output:

<?xml version="1.0" encoding="UTF-8"?>
<gexf xmlns="http://www.gexf.net/1.2draft" 
xmlns:viz="http://www.gexf.net/1.1draft/viz" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://www.gexf.net/1.2draft http://www.gexf.net/1.2draft/gexf.xsd" version="1.2">
  <graph mode="static">
    <nodes>
      <node id="1" label="juan"/>
      <node id="2" label="pedro"/>
      <node id="3" label="matthew"/>
      <node id="4" label="carlos"/>
    </nodes>
    <edges>
      <edge source="1" target="4"/>
      <edge source="1" target="2"/>
      <edge source="1" target="3"/>
      <edge source="2" target="3"/>
      <edge source="3" target="4"/>
      <edge source="4" target="2"/>
    </edges>
  </graph>
</gexf>

Example 2: Dynamic net

Defining the dynamic structure, note that there are some nodes that have NA at the end.

> time<-matrix(c(10.0,13.0,2.0,2.0,12.0,rep(NA,3)), nrow=4, ncol=2)
> time
     [,1] [,2]
[1,]   10   12
[2,]   13   NA
[3,]    2   NA
[4,]    2   NA

Getting things done

> write.gexf(people, relations, nodeDynamic=time)

output

<?xml version="1.0" encoding="UTF-8"?>
<gexf xmlns="http://www.gexf.net/1.2draft" 
xmlns:viz="http://www.gexf.net/1.1draft/viz" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://www.gexf.net/1.2draft http://www.gexf.net/1.2draft/gexf.xsd" version="1.2">
  <graph mode="dynamic" start="2" end="13" timeformat="double" defaultedgetype="undirected">
    <nodes>
      <node id="1" label="juan" start="10" end="12"/>
      <node id="2" label="pedro" start="13"/>
      <node id="3" label="matthew" start="2"/>
      <node id="4" label="carlos" start="2"/>
    </nodes>
    <edges>
      <edge source="1" target="4"/>
      <edge source="1" target="2"/>
      <edge source="1" target="3"/>
      <edge source="2" target="3"/>
      <edge source="3" target="4"/>
      <edge source="4" target="2"/>
    </edges>
  </graph>
</gexf>

Example 3: Node/Edge at a time

rgexf also supports writing graphs one element at a time.

Creating an empty graph (gexf object)

> mygraph <- new.gexf.graph()

Adding some nodes

> mygraph <- add.gexf.node(mygraph, id=0, label="He")
> mygraph <- add.gexf.node(mygraph, id=1, label="Her")

Adding some edges and dynamics

> mygraph <- add.gexf.edge(mygraph, id=0, source=0, target=1, start=10, end=15)
> mygraph <- add.node.spell(mygraph, id=1, start=3, end=18)