Problem with Linprog: it says it is infeasible while it is feasible

Hi all,

I use linprog to optimize a problem. One of my inequality constraint is: Area * X <= Capacity . When I use this constraint, the linprog says the problem is infeasible but when I use X <= Capacity / Area , the problem becomes feasible. I want to optimize the problem on different data. On most of the data, X <= Capacity / Area makes the problem feasible and sometimes Area * X <= Capacity is helpful. What is the problem and how can I solve it?

another problem is the value of Capacity. Mathematically, when I increase the value of Capacity, the problem should remain feasible but in Linprog, I can not increase this value very much, it gives exitflag = -2 or -3. Why?

Thanks in advance for your help.

Cheers, Soroor

Answer 1

[Sean de Wolski]

Do the bounds make it infeasible?

Answer 2

[soroor sarafrazi]

if you mean lb and ub, the answer is "No".

[Sean de Wolski]

There's probably not much else we can help with without seeing the data and code. Can you attach it (as zip file)?

[soroor sarafrazi]

Thanks and sorry for the late reply. I simplified the model which helped to avoid the error magnification.