This function extract relations between all of the leaves from a phylogenetic tree (NEWICK format) into excel format. The output file (.xls) contains both a contingency matrix summarizing pairwise combinations their proportions from 2 levels of terminal branches This function is currently under development. For détails see Kandoussi et al. (2020) Kandoussi, A., Boujenane, I., Auger, C., Serranito, B., Germot, A., Piro, M., Maftah, A., Badaoui, B., Petit, D., 2020. The origin of sheep settlement in Western Mediterranean. Sci Rep 10, 10225. https://doi.org/10.1038/s41598-020-67246-5 More explanations will be provided later...