How to write a negative objective function for fmincon

Hello togehter,

I want to maximize the follwing objective funtion :(30x1+15x2)². Usually the objective function in Matlab wants to minimize. Therefore I tried to set the function as (-30x1-15x2)^2. But I always receive the error "Function definitions are not permitted in this context".

Could you please help me?

Answer 1

[Star Strider]

If that is actually the function you want to maximize, use an anonymous function as your objective function:

f = @(x) (30.*x(1) + 15*x(2)).^2;
xv = fmincon(@(x)-f(x), ... );

Note that this negates the evaluated result of the function call. If you negate within the expression, then square it, the result will always be positive.

[Lukas Langer]

Thanks for your quick support!

[Star Strider]

As always, my pleasure!