Previously the PMXCrossover.execute function was returning a child solution with variables field referring to parts of parents' variables. It is due to variables being a list of lists, so the slice operator in _swap function was just copying the references of the lists in the list.
It resulted in unexpected behaviours like child mutation affecting its parents, which led to e.g. wrong solutions being reported as best.
Previously the
PMXCrossover.executefunction was returning a child solution withvariablesfield referring to parts of parents'variables. It is due tovariablesbeing a list of lists, so the slice operator in_swapfunction was just copying the references of the lists in the list.It resulted in unexpected behaviours like child mutation affecting its parents, which led to e.g. wrong solutions being reported as best.