In a directed network, two nodes *(A, B)* are said to have a reciprocal relationship if there exists an edge from A to B and from B to A. The reciprocity is the ratio of reciprocal relationships in the network in to the total number of relationships (reciprocal or otherwise) in the network.

A dyad is defined as any pair of actors (nodes) (A, B). In a directed network there are three possible kinds of dyads, no tie (link), one likes the other but not vice versa (AB or BA exists, but not both), or both like the other (AB and BA exist). The last one corresponds to a reciprocal relation and a reciprocated tie.

The prevalence of reciprocity is given by the ratio of number of ties involved in reciprocal relations to the total number of ties present in the network.

Algorithm must be applied to directed networks. Self-loops are ignored in the calculation.

This is global calculation for the input network, and as such the results are simply reported on the Console window.

- Source Code: link

Hanneman, Robert A. and Mark Riddle. 2005. Introduction to social network methods. Riverside, CA: University of California, Riverside.

http://faculty.ucr.edu/~hanneman/nettext/