obj_scaling_factor:

Scaling factor for the objective function. $\;$
This option sets a scaling factor for the objective function. The scaling is seen internally by Ipopt but the unscaled objective is reported in the console output. If additional scaling parameters are computed (e.g. user-scaling or gradient-based), both factors are multiplied. If this value is chosen to be negative, Ipopt will maximize the objective function instead of minimizing it. The valid range for this real option is ${\tt -inf} < {\tt obj\_scaling\_factor } < {\tt +inf}$ and its default value is $1$ .