What is the difference between Ward clustering and SOM-Ward clustering?
The SOM-Ward clustering is based on the SOM-Ward distance, which is a variant of the Ward distance. The Ward distance between two clusters is defined as dxy := nx * ny / (nx + ny) * norm(meanx – meany)2 where nx and ny are the numbers of data points and meanx and meany the centers of gravity of the clusters; norm() is the Euclidean norm.
