I was looking at the knights tour problem and decided to have a go at implementing it in python using a neural network to find solutions.
The general explanation of the method can be found on Wikipedia
While I think I have implemented it correctly (I can’t see anything else that is wrong), it doesn’t work, it updates a few links, removing the edges where the connecting vertex has a degree more than two, but it doesn’t converge on the solution.
I was wondering if anyone had any ideas on what I have implemented incorrectly (Sorry about the horrible code).
EDIT
Working code can be found at GitHub https://github.com/Yacoby/KnightsTour
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Answer
You can’t update the neurons in place. Since U[t+1] depends on U[t] and V[t], if you have already updated V the calculation for U will be wrong
I think you should split the update into two phases update_state and update_output, so all the U are updated and then all the V
for n in neurons: n.update_state() for n in neurons: n.update_output()