classifies the observations into groups according to the k-means classification
function[res]=kcmeans(xi,ngroup,nchanged)
a matrix (n x q) or a Div structure
number of groups for the classification
stops when nchanged classes have changed at the previous step
classification of the observations within groups
res.group.d is a vector of dimensions (n x 1) giving the group (1 ou 2… ou ngroup) for each observation
barycenters of the groups
res.barycenter.d is a matrix of dimensions (ngroup x q)