data(ecoli)
R
package.ecoli1
is directed, with 423 nodes and 519 arcs.
The object ecoli2
is an undirected version of the same network, in
which all arcs are treated as edges and the five isolated nodes (which exhibit
only self-regulation in ecoli1
) are removed, leaving 418 nodes.Shen-Orr et al (2002), Network Motifs in the Transcriptional Regulation Network of Escerichia Coli, Nature Genetics, 31(1): 64-68.