# write.graph

0th

Percentile

##### Writing the graph to a file in some format

write.graph is a general function for exporting graphs to foreign file formats, however not many formats are implemented right now.

Keywords
graphs
##### Usage
write.graph(graph, file, format=c("edgelist", "pajek", "ncol",
"lgl", "graphml", "dimacs", "gml", "dot", "leda"), ...)
##### Arguments
graph
The graph to export.
file
A connection or a string giving the file name to write the graph to.
format
Character string giving the file format. Right now pajek, graphml, dot, gml, edgelist, lgl, ncol and dimacs are implemented. As of igraph
...
Other, format specific arguments, see below.
##### Value

• A NULL, invisibly.

##### Edge list format

The edgelist format is a simple text file, with one edge in a line, the two vertex ids separated by a space character. The file is sorted by the first and the second column. This format has no additional arguments.

##### Pajek format

The Pajek format is a text file, see read.graph for details. Appropriate vertex and edge attributes are also written to the file. This format has no additional arguments.

##### GraphML format

The GraphML format is a flexible XML based format. See read.graph for GraphML details. Vertex and edge attributes are also written to the file. This format has no additional arguments.

##### Dot format

The dot format is used by the popular GraphViz program. Vertex and edge attributes are written to the file. There are no additional arguments for this format.

##### References

Adai AT, Date SV, Wieland S, Marcotte EM. LGL: creating a map of protein function with an algorithm for visualizing very large biological networks. J Mol Biol. 2004 Jun 25;340(1):179-90.

read.graph
g <- graph.ring(10)
write.graph(g, "/tmp/g.txt", "edgelist")