Improvements in "AEC.03 - Solving the TSP with GAs"

[solarjoe]

Hello,

I found your TSP example very useful. There is a small issue that I came across.

I found that using a set() in generate_cities(n) leads to problems with the indexing for larger problems. As a set has no fixed order the expression list(set()) in create_tour used later might reorder the elements.

There is also a TSP example in the DEAP repository:
https://github.com/DEAP/deap/blob/master/examples/ga/tsp.py

Instead of toolbox.register("mate", tools.cxOrdered) they use toolbox.register("mate", tools.cxPartialyMatched) but I don't know what exactly the difference is.