MILP - Multidimensional optimization
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Hi guys, I am currently working on an optimization problem:-
I have to assign my workers (i) to perform different tasks (j) under different sections (k) of different projects(L).
So I created a simple model : Maximize P = X(ijkl)*Y(ijkl) and Y(ijkl) is binary variable
The assignment method are based on the performance data X(ijlk), e.g. workers (i) have 20 marks in task (j) under section (k) in project (L).
But I have problem in creating the performance data in matlab. I have tried to create 4-D matrix but error occur. Can anyone give me some advise?
Thank you. Jim
---Updated---
Here is my code
l = {'P1','P2',};
k = {'S1','S2','S3','S4'};
j = {'T1','T2','T3','T4','T5','T6','T7', 'T8'};
i = {'W1','W2','W3','W4','W5','W6','W7','W8'};
Y = optimvar('Y',i,j,k,l,'LowerBound',0,'UpperBound',1,'Type','integer');
X = rand(8,8,4,2)
Optimprob = optimproblem('ObjectiveSense','maximize','Objective',sum(sum(Y.*X)));
[soln,fval,exitflag,output] = solve(Optimprob);
and turns out error is occur:-
Error using optimproblem (line 52) Objective must be a scalar OptimizationExpression or a struct containing a scalar OptimizationExpression.
2 个评论
Alan Weiss
2018-8-28
Please show us some code and the full error message.
Alan Weiss
MATLAB mathematical toolbox documentation
Ngai Nang Wong
2018-8-28
回答（2 个）
Aurele Turnes
2018-9-11
编辑：Aurele Turnes
2018-9-11
Your objective is
obj = sum(sum(Y.*X))
which is not scalar, but a 1-by-1-by-4-by-2 ND array.
Currently, the problem-based optimization only supports linear and mixed-integer linear problems: https://www.mathworks.com/help/optim/problem-based-lp-milp.html
All these solvers expect the objective to return a scalar value, so the objective is expected to be a 1-by-1 expression.
BOWEN LI
2019-7-19
0 个投票
Hi, I am working on a similar question as yours, have you solved this question?
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2018-8-28
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