Reordered co-cluster matrix reveals co-clustering patterns. (a) Values in the co-cluster matrix range from 1 (light pink) to 9 (red) for nine clusterings of the A. thaliana PPI network with 2402 proteins from . Pink regions represent item pairs that were placed in the same module by very few clusterings while regions of more saturated red represent proteins that co-clustered in most clusterings. Black indicates that the items never co-clustered. On the inset matrix, the matrix items under the green square formed a core. A large blue square overlay suggests that the core was tightly integrated into the rest of the network. (b) Left: nodes that formed a core in (a) are colored green, the edges between the nodes within the core are colored blue. The inset to the right shows an isolated view of the core nodes (green), edges between core nodes (blue), and nodes one hop away from the core nodes (gray). Green nodes share many edges with nodes outside of the core which resulted in the core’s low cohesion.
Filippova et al. BMC Bioinformatics 2012 13:276 doi:10.1186/1471-2105-13-276