Group average We consider two clusters C: and C which are of sizes m and respectively. The distance between the two clusters can be expressed by the following equation XEC vEC a(X, y d(cici) m 8/20/2016 PATTERN RECOGNITIONGroup average We consider two clusters Ci and Cj , which are of sizes mi and mj respectively. The distance between the two clusters can be expressed by the following equation 𝑑 𝐶𝑖 , 𝐶𝑗 = σ𝐱∈𝐶𝑖 ,𝐲∈𝐶𝑗 𝑑 𝐱, 𝐲 𝑚𝑖𝑚𝑗 8/20/2016 PATTERN RECOGNITION 58