Implement the Travelling salesman problem

Question

Stefan Zeiter 2018-3-31

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/391852-implement-the-travelling-salesman-problem

回答： Alan Weiss 2018-4-2

TSP.txt

Hey

I would like to implement the branch and bound algorithm to solve the TSP. For achieving this task I found good inputs at this website: https://ch.mathworks.com/help/optim/examples/travelling-salesman-problem.html

Attached you can find my script. At the moment I get following error message:

>> TSP Error using optim.problemdef.OptimizationProblem/solve options is not a valid solver. Use 'linprog' or 'intlinprog' instead.

Error in TSP (line 71) tspsol = solve(tsp,'options',opts)

Could someone help me to solve this problem? I don't know where is the fault. I have also an additional question. Is my script working with the branch and bound algorithm? I would guess so because the scripts contains constraints and subconstraints. But I'm not sure...

Best

3 个评论
显示 1更早的评论隐藏 1更早的评论

Stefan Zeiter 2018-3-31

Thanks for your reply

I have the version R2017b.

Stefan Zeiter 2018-3-31

I guess this is the second newest version.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

John D'Errico 2018-3-31

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/391852-implement-the-travelling-salesman-problem#answer_312905

编辑：John D'Errico 2018-3-31

在 MATLAB Online 中打开

Your problem is here:

tspsol = solve(tsp,'options',opts)

which should be:

tspsol = solve(tsp,opts)
tspsol = 
  struct with fields:
      trips: [19900×1 double]

As you can see, my release (also R2017b) has no problem.

3 个评论
显示 1更早的评论隐藏 1更早的评论

John D'Errico 2018-4-1

NO. You do NOT define a variable named updateSalesmanPlot. That is expected to be a function. When you created it as a variable, it tries to index into the variable, instead of calling a function by that name.

Stefan Zeiter 2018-4-1

编辑：Stefan Zeiter 2018-4-1

okay...

So you have an idea how I can prevent the Error message at line 80?

Subscript indices must either be real positive integers or logicals.

Error in TSP (line 80)

lh = updateSalesmanPlot(lh,tspsol.trips,idxs,stopsLon,stopsLat);

请先登录，再进行评论。

Answer 2

Alan Weiss 2018-4-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/391852-implement-the-travelling-salesman-problem#answer_313099

From the example that you mentioned click the "Try this example" button in MATLAB (not in your browser). This will take your MATLAB to the appropriate folder, containing the updateSalesmanPlot function, so MATLAB can find it.

Alan Weiss

MATLAB mathematical toolbox documentation