Dear All, I am not that much into machine learning, but I know that R is wonderful at that. My problem is the following: consider a set of N individuals and an N by N symmetric matrix M. This matrix stands for an interaction between individuals, i.e. the element M[i,j]=M[j,i] is the (cumulative) amount of time that individuals i and j spent together. Now, the diagonal of the matrix is probably not meaningful (M[j,j] could at most tell me for how long I have been observing every individual j, but I would leave it out of the discussion). In other words, for any individual j, I know all the individuals s/he interacted with and for how long. Finally, the individuals {j} are partitioned into 5 classes A,B,C,D,E. The idea would be to train an algorithm on the matrix P (which is defined exactly as M but on a subset of the set of individuals {j}) and test its capability of predicting the classes the other individuals (for whom I generate another interaction matrix Q) belong to. Does anybody know how to achieve that? In a sense, I want to get a "collision kernel" telling me how likely is an individual characterized by a certain set of contacts and associated contact durations to belong to class A,B...E. Any suggestion is welcome. Best Regards Lorenzo