Define a optimization problem

Hi my dears!

I am try solving a optimization problem with the above equation and constraint :

F.O : 43120*x+23800*y+47750*z

Subject to:

9*x+12*y+9*z <= 690

9.57*x+4.28*y+12.44*z <= 130

x<= 10

y<= 16

z<= 8

I used the follow script:

x = optimvar('x');
y = optimvar('y');
z = optimvar('z');
prob = optimproblem;
prob.Objective = 43120*x+23800*y+47750*z;
prob.Constraints.cons1 = (9/690)*x + (12/690)*y +(9/690)*z <= (690/690);
prob.Constraints.cons2 = 9.57*x + 4.28*y+12.44*z <= 130;
prob.Constraints.cons3 = x <= 10;
prob.Constraints.cons4 = y <= 16;
prob.Constraints.cons5 = z <= 8;

sol = solve(prob,'Solver', 'intlinprog')

When I run, show the message:

Solving problem using intlinprog.

Problem is unbounded.

No integer variables specified. Intlinprog stopped because the linear problem is unbounded.

Can help me, please?

Thank you!

Answer 1

[Alan Weiss]

Perhaps you left out constraints that the x, y, and z variables should be nonnegative. Put those constraints and the upper bound constraints into your optimvar calls:

x = optimvar('x','LowerBound',0,'UpperBound',10);
y = optimvar('y','LowerBound',0,'UpperBound',16);
z = optimvar('z','LowerBound',0,'UpperBound',8);

If you want them to be integer-valued rather than real-valued, set their Type to 'integer'. And don't bother settng the Solver argument of solve, it will choose an appropriate solver.

And if you want to maximize the objective rather than minimize, set the optimproblem ObjectiveSense to 'maximize'.

Alan Weiss

MATLAB mathematical toolbox documentation

[Guilherme Lopes de Campos]

Thank you so much Alan Weiss

I am very grateful to you