Optional
alphaThe alpha value for the centrality calculation, ranging on [0, 1]. With value 0 (default), disregards edge weights and solely uses number of edges in the centrality calculation. With value 1, disregards number of edges and solely uses the edge weights in the centrality calculation.
Optional
directedWhether the directed indegree and outdegree centrality is calculated (true) or whether the undirected centrality is calculated (false, default).
The root node (selector or collection) for which the centrality calculation is made.
Optional
weightA function that returns the weight for the edge.
http://js.cytoscape.org/#eles.degreeCentrality