knn_distances           Distances matrixes computation and saving in
                        files with a maximum of columns
knn_elements            'Elements' matrix computation
knn_next                Next value prediction
knn_optim               k and d optimization
knn_optim_parallel      Parallel k and d optimization
knn_optim_parallel2     Parallel k and d optimization
knn_optim_parallelf     Parallel k and d optimization reading from
                        files
knn_past                Past time prediction
