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Showing posts from May, 2026

Matching networks, matrices, and dendrograms

Consider the three small networks below, the adjacency matrix M, and the three dendrograms in shuffled order produced by hierarchical clustering applied to each graph's shortest-path distance matrix, where the dashed red line shows a cut that creates community partitions. Graph A 1 2 3 4 5 6 Graph B 1 2 3 4 5 6 Graph C 1 2 3 4 5 6 Dendrogram 1 1 2 3 4 5 6 Dendrogram 2 1 2 3 4 5 6 Dendrogram 3 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 0 1 1 0 0 0 1 0 1 0 0 0 1 1 0 1 0 0 0 0 ...

Pearson degree-correlation coefficient

Consider the network below: A B C D E What is the Pearson degree correlation coefficient (r) for this network using Mark Newman's definition? A. r = 0, since the average degree of every node’s neighbors equals ⟨k⟩. B. r = -2/3, indicating the network is assortative. C. r = +2/3, indicating the network is disassortative. D. r = -1/2, indicating the network is assortative. E. None of the above. Original idea by: Gustavo P. C. P. da Luz