MATLAB: Fmincon is not feasible

Question

I am trying to solve some sort of gradient projection problem , using fmincon. The problem is as follows:

 min C*x
   Aeq*x = 0
   lb <= x <= ub

where lb and ub are some real vectors(between -10 and 10) and x is a vector as well. I set starting point to be 0, and have not change the other parameters of fmincon. The problem is fminco return non-feasible solutions with following massage:

 fmincon stopped because it exceeded the function evaluation limit,

Note: some elements of ub are equal to zero, as well as all elements of x0.

Any suggestion for fixing the problem?

Answer 1

Use linprog instead of fmincon.

Best wishes

Torsten.