“…Many approaches for fitting a structure to a single proximity matrix (with rows and columns corresponding to the same set of objects) require the identification of a reordering (or permutation) of the rows and columns of the matrix that optimizes some type of index Brusco & Stahl, 2001;Hubert, 1976Hubert, , 1978Hubert & Golledge, 1981b;Hubert & Schultz, 1976;Hubert, Arabie, & Meulman, 2001). Such problems are inherently combinatorial in nature and can frequently be described within the context of some broader framework, such as the quadratic assignment paradigm (Hubert & Schultz, 1976;Hubert et al, 2001).…”