som_neighbors

Ne = som_neighbors(sM,neigh)

 Ne = som_neighbors(sM,neigh)

 sM      (struct) map or data struct
         (matrix) data matrix, size n x dim
 [neigh] (string) 'kNN' or 'Nk' (which is valid for a SOM only)
                  for example '6NN' or 'N1'
                  default is '10NN' for a data set and 'N1' for SOM

 Ne      (matrix) size n x n, a sparse matrix
                  indicating the neighbors of each sample by value 1 
                  (note: the unit itself also has value 0)