Supplement 1. R code for the algorithm used in this paper.

File List compelt.r – R source code Description The compelt.r R program allows the generation of all possible combinations of a given list of chemical elements and compute the discrimination accuracy for each combination. Details of the inputs taken by the program and possible options are given in the header of the program. The outputs of the programs are tables given minimal, maximal and mean accuracies obtained for each size of combination, and a graphical view of this result is built.