Objective value
Signature
objective_value(Solution) : double[0..1]
Description
This function produces the value of the objective function at the given solution if the solution is feasible, and no value otherwise. A solution is feasible if it satisfies all constraints of the problem. The objective value of an infeasible solution is undefined.
In general, both complete and partial solutions may be feasible or infeasible. Feasible partial solutions are common, for example, in models of the knapsack problem, as even an empty knapsack is a feasible solution. Infeasible complete solutions may arise, for example, when constructing solutions for the travelling salesman problem on incomplete graphs.
Evaluation of the objective function must occur before this function returns, but the time at which the evaluation actually occurs is otherwise unspecified.
It is assumed that the objective function is to be minimised.
Use cases
Objective-value evaluation is required by all optimisation algorithms.