public static int Main(string[] args)
{
string modelDirectory = ((args != null) && (args.Length > 0)) ? args[0]
: "../../models";
string solver = ((args != null) && (args.Length > 1)) ? args[1] : null;
/*
* // If the AMPL installation directory is not in the system search path:
* ampl.Environment env = new ampl.Environment(
* "full path to the AMPL installation directory");
* // Create an AMPL instance
* using (AMPL a = new AMPL(env)) {}
*/
// Create an AMPL instance
using (AMPL a = new AMPL())
{
if (solver != null)
{
a.SetOption("solver", solver);
}
// Interpret the two files
a.Read(System.IO.Path.Combine(modelDirectory, "diet/diet.mod"));
a.ReadData(System.IO.Path.Combine(modelDirectory, "diet/diet.dat"));
// Solve
a.Solve();
// Get objective entity by AMPL name
Objective totalcost = a.GetObjective("Total_Cost");
// Print it
Console.WriteLine("ObjectiveInstance is: {0}", totalcost.Value);
// Reassign data - specific instances
Parameter cost = a.GetParameter("cost");
cost.SetValues(ampl.Tuple.FromArray("BEEF", "HAM"),
new double[] { 5.01, 4.55 });
Console.WriteLine("Increased costs of beef and ham.");
// ReSolve and display objective
a.Solve();
Console.WriteLine("Objective value: {0}", totalcost.Value);
// Reassign data - all instances
cost.SetValues(new double[] { 3, 5, 5, 6, 1, 2, 5.01, 4.55 });
Console.WriteLine("Updated all costs");
// ReSolve and display objective
a.Solve();
Console.WriteLine("New objective value: {0}", totalcost.Value);
// Get the values of the variable Buy in a dataframe object
Variable Buy = a.GetVariable("Buy");
// Access a specific instance (method 1)
Console.WriteLine(Buy.Get("FISH").ToString());
// Access a specific instance (method 2)
Console.WriteLine(Buy[new ampl.Tuple("FISH")].ToString());
DataFrame df = Buy.GetValues();
// Print them
Console.WriteLine(df);
// Get the values of an expression into a DataFrame object
DataFrame df2 = a.GetData("{j in FOOD} 100*Buy[j]/Buy[j].ub");
// Print them
Console.WriteLine(df2);
}
return(0);
}
