Exemple #1
0
        /// <summary>
        /// I used this Gurobi model to calculate the fixed point baseline.
        /// </summary>
        public mae_sdo()
        {
            string path = @"C:\Users\Roman Bolzern\Desktop\D4\neu\meta_data_training.csv";

            var lines = File.ReadLines(path).ToArray();

            GRBEnv   env = new GRBEnv();
            GRBModel m   = new GRBModel(env);

            var scale = 1e9;

            var y = m.AddVar(1e-9 * scale, 1e-2 * scale, 0d, GRB.CONTINUOUS, "y");

            var obj = new GRBLinExpr();

            for (int i = 1; i < lines.Length; i++)
            {
                var diff      = double.Parse(lines[i].Split(',')[3]) * scale - y;
                var diffinput = m.AddVar(-1e-2 * scale, 1e-2 * scale, 0d, GRB.CONTINUOUS, "diffinput");
                m.AddConstr(diffinput == diff);
                var diffres = m.AddVar(0, 1e-2 * scale, 0d, GRB.CONTINUOUS, "diffres");
                m.AddGenConstrAbs(diffres, diffinput, "diffAbs");
                obj += diffres;
            }

            m.SetObjective(obj, GRB.MINIMIZE);
            m.Optimize();

            Console.WriteLine($"Objective: {((GRBLinExpr)m.GetObjective()).Value / scale}");
            Console.WriteLine($"fixed point: {y.X / scale}");
        }
        public override double GetObjective(object solver)
        {
            GRBModel grbSolver = solver as GRBModel;

            if (grbSolver == null)
            {
                return(0.0);
            }
            return(((GRBLinExpr)grbSolver.GetObjective()).Value);
        }
        public override bool SetObj(object solver, int Column, double Value)
        {
            GRBModel grbSolver = solver as GRBModel;

            if (grbSolver == null)
            {
                return(false);
            }
            GRBLinExpr exp = grbSolver.GetObjective() as GRBLinExpr;

            exp.AddTerm(Value, exp.GetVar(Column));
            return(true);
        }