Matrix of vertex similarities Θ (i,i′) (top) and matrix of correlations between the edge weights of vertices i in G and i′in G′(correlation of i’th column of A and i′’th column of A′,cor(i,i′), bottom) for the scenario (iii) and network size N = 200. The optimal alignment of the two networks aligns the n-th vertex of G to the n-th vertex of G′. Half of the diagonal terms represents truly orthologous vertices with both vertex and topological similarity (highlighted in green). The other 10% of vertices i in G (highlighted in blue) have two possible vertex similar partners in network G′, one of them with a strong topological match (the true ortholog) and the other with no match (the spurious ortholog). Next, there are 20% of vertices with no vertex similarity but strong topological similarity (analogs, highlighted in red). Scattered off-diagonal terms in θ model spurious weak vertex similarities in the data.