Obtaining the Maximum and Minimum and their Orders, Ordering and the Histogram of an Array of Real Numbers with a MILP Model

In a previous work we solved the same problem with real numbers with limited precision, but we did not consider the possibility of repetitions. In this paper we used a new, simpler and more efficient approach where the coherence between the original set and the ordered set is guaranteed by an auxiliary indexed binary variable and two sets of constraints that implement the restriction to a binary variable, a linearization technique developed in a previous work [1]. We also obtained the order in the original set of each element of the ordered set, the maximum(s) and minimum(s) and their orders with another auxiliary indexed binary variable and two sets of constraints and obtained the histogram of the original set of real numbers. Then we presented some examples of computational experiments that show that this new approach is more efficient in terms of runtime and memory usage. Finally we point as the improvement of the histogram calculation as the near future work.