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Objective Variables

Objective Variables

Objective variables are defined to construct an objective function. The objective function is a summation of all variables that are designated as objective-type. Variables are defined as objective function contributions by starting with obj. Thus, the variables obj1, objective, object[1] would be included in the objective function summation.

Additionally, slack variables are included in the objective function. These variables begin with the key letters slk and are defined with a lower bound of zero.

Minimize vs. Maximize

The objective function is always minimized with APMonitor. Objective function maximization is accomplished by defining a new variable that is the negative of the minimized objective.

Example

 ! Example model with an objective function
 Model example
   Parameters
     p1 = 5
   End Parameters

   Variables
     objective
     v1 > 6
   End Variables

   Equations
     objective = (v1 - p1)^2
   End Equations
 End Model

 Solution
  p1 = 5
  v1 = 6
  objective = 1