depot Location allocation problem

2014 12 10
1 个回答
回答已采纳
更新时间：2014 12 11
7 次查看（30 天）

0 个投票

Hello,
I am trying to solve a depot location allocation problem . I am unable to formulate and solve it in MATLAB. Can anyone help me solve this problem?

请先登录，再回答此问题。

 采纳的回答

Alan Weiss
Alan Weiss 2014-12-10

1 个投票

Maybe you could put your problem in an MILP framework, along the lines as this Travelling Salesman Problem example. Notice that, despite the nonlinear distances, the problem itself is linear.
This example might also be relevant: Factory, Warehouse, Sales Allocation Model.
Alan Weiss
MATLAB mathematical toolbox documentation

4 个评论
显示 2更早的评论 隐藏 2更早的评论

blitz
blitz 2014-12-11
编辑：blitz 2014-12-11
Thanks Alan, I have figured out to code this but still my solution doesn't converge to optimum rather it stays at my initial guess of depot locations. Here is my code. This is for 4 customers and 3 depots. Code doesn't give any error but location of my depot doesn't change from what i give in initial guess. Can you find out what I am missing here? Thanks
fun2=@(z)cost_function2(zvectorized,Cvec,M,N); options = optimoptions(@fmincon,'Algorithm','sqp'); options.Display='iter'; [zfinal,fval,exitflag,output]=fmincon(fun2,z0,[],[],Aeq,beq,lb,[],[],options);
Cost function:
function cost = cost_function2(Z,Cvec,M,N) %UNTITLED4 Summary of this function goes here xcoeff=Z(1:2*M,1); Xvec=reshape(xcoeff,2,M); tcoeff=Z((2*M)+1:(M*N)+2*M,1); t=reshape(tcoeff,M,N); cost=0;
for i=1:M for j=1:N cost=cost+t(i,j)*sqrt((Xvec(:,i)-Cvec(:,j))'*(Xvec(:,i)-Cvec(:,j))); end end end
OUTPUT:
zfinal =
0
0
0
0
0
0
1.6667
1.6667
1.6667
2.0000
2.0000
2.0000
2.3333
2.3333
2.3333
1.3333
1.3333
1.3333
So locations are all zeros which mean the solution wasn't obtained. Please help.
Alan Weiss
Alan Weiss 2014-12-11
编辑：Alan Weiss 2014-12-11
It would be much easier for us to read your question if you would format the MATLAB code using the {} Code button.
I do not understand your code, but then I have trouble reading it because of the formatting. Nevertheless, I think I found an error:
fun2=@(z)cost_function2(zvectorized,Cvec,M,N);
It seems to me that fun2 returns a constant no matter what value you put in for z. Perhaps you meant
fun2=@(zvectorized)cost_function2(zvectorized,Cvec,M,N);
Alan Weiss
MATLAB mathematical toolbox documentation
blitz
blitz 2014-12-11
Thank you so much! You're awesome, that worked. I just couldn't believe I was missing such a detail. I up-voted the answer. Sorry about the bad arrangement of code. I am new to this and didn't know about it. I thank you once again.
Image Analyst
Image Analyst 2014-12-11
Please read this: http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup
In the meantime, Mathworkers and others with enough reputation points can "Edit" the post to see the code in a form better for viewing and copying and pasting.

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Get Started with MATLAB 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by