Author(s)

Gilad Barach, Hugo Fort, Yoni Mehlman, Fredy Zypman

Facultad de Ciencias, Departamento de Física, Montevideo, Uruguay.
Yeshiva University, Department of Physics, New York, NY 10033, USA.

In the Simulated Annealing algorithm applied to the Traveling Salesman Problem, the total tour length decreases with temperature. Empirical observation shows that the tours become more structured as the temperature decreases. We quantify this fact by proposing the use of the Shannon information content of the probability distribution function of inter–city step lengths. We find that information increases as the Simulated Annealing temperature decreases. We also propose a practical use of this insight to improve the standard algorithm by switching, at the end of the algorithm, the cost function from the total length to information content. In this way, the final tour should not only be shorter, but also smoother.

Traveling Salesman Problem; Shannon Entropy

G. Barach, H. Fort, Y. Mehlman and F. Zypman, "Information in the Traveling Salesman Problem," Applied Mathematics, Vol. 3 No. 8, 2012, pp. 926-930. doi: 10.4236/am.2012.38138.