apis/examples_dotnet/GMSWarehouse_8cs_source.html

using System;

 using System.IO;

 using GAMS;


 namespace Warehouse

 {

     class Warehouse

     {

         private static int status = 0;

         private static string statusString = string.Empty;

         private static void SolveWarehouse(GAMSWorkspace gmsWS, int NumberOfWarehouses, GAMSDatabase result, Object dbMutex)

         {

             GAMSJob gmsJ = gmsWS.AddJobFromString(GetModelText());

             try

             {

                 // instantiate GAMSOptions and define some scalars

                 GAMSOptions gmsOpt = gmsWS.AddOptions();

                 gmsOpt.AllModelTypes = "cplex";

                 gmsOpt.Defines.Add("Warehouse", NumberOfWarehouses.ToString());

                 gmsOpt.Defines.Add("Store", "65");

                 gmsOpt.Defines.Add("fixed", "22");

                 gmsOpt.Defines.Add("disaggregate", "0");

                 gmsOpt.OptCR = 0.0; // Solve to optimality


                 // create a GAMSJob from string and write results to the result database

                 gmsJ.Run(gmsOpt);


                 // need to lock database write operations

                 lock (dbMutex)

                     result.GetParameter("objrep").AddRecord(NumberOfWarehouses.ToString()).Value = gmsJ.OutDB.GetVariable("obj").FindRecord().Level;


                 foreach (GAMSVariableRecord supplyRec in gmsJ.OutDB.GetVariable("supply"))

                     if (supplyRec.Level > 0.5)

                         lock (dbMutex)

                             result.GetSet("supplyMap").AddRecord(NumberOfWarehouses.ToString(), supplyRec.Key(0), supplyRec.Key(1));

             }

             catch (GAMSExceptionExecution e)

             {

                 // Check if we see a User triggered abort and look for the user defined result

                 if (e.eRC == GAMSExitCode.ExecutionError)

                     lock (dbMutex)

                         statusString = gmsJ.OutDB.GetSet("res").FindRecord(gmsJ.OutDB.GetSet("ares").FirstRecord().Key(0)).Text;

                 lock (dbMutex)

                     status = e.iRC;

             }

             catch (GAMSException e)

             {

                 Console.WriteLine(e.Message);

                 lock (dbMutex)

                     status = -1;

             }

             catch (Exception e)

             {

                 Console.WriteLine(e.Message);

                 lock (dbMutex)

                     status = -2;

             }

         }


         static void Main(string[] args)

         {

             GAMSWorkspace gmsWS;

             if (Environment.GetCommandLineArgs().Length > 1)

                 gmsWS = new GAMSWorkspace(systemDirectory: Environment.GetCommandLineArgs()[1]);

             else

                 gmsWS = new GAMSWorkspace();


             // create a GAMSDatabase for the results

             GAMSDatabase resultDB = gmsWS.AddDatabase();

             resultDB.AddParameter("objrep",1,"Objective value");

             resultDB.AddSet("supplyMap",3,"Supply connection with level");


             try

             {

                 // run multiple parallel jobs

                 Object dbLock = new Object();

                 System.Threading.Tasks.Parallel.For(10, 22, delegate(int i) { SolveWarehouse(gmsWS, i, resultDB, dbLock); });

                 if (status > 0)

                 {

                     throw new GAMSExceptionExecution("Error when running GAMS: " + (GAMSExitCode)status + " " + statusString, status);

                 }

                 else if (status == -1)

                 {

                     throw new GAMSException("Error in GAMS API");

                 }

                 else if (status == -2)

                 {

                     throw new Exception();

                 }

                 // export the result database to a GDX file

                 resultDB.Export("\\tmp\\result.gdx");

             }

             catch (GAMSException ex)

             {

                 Console.WriteLine("GAMSException occured: " + ex.Message);

             }

             catch (System.Exception ex)

             {

                 Console.WriteLine(ex.Message);

             }

             finally

             {

                 resultDB.Dispose();

             }


             Environment.ExitCode = status;

         }


         static String GetModelText()

         {

             String model = @"

 $title Warehouse.gms


 $eolcom //

 $SetDDList warehouse store fixed disaggregate // acceptable defines

 $if not set warehouse    $set warehouse   10

 $if not set store        $set store       50

 $if not set fixed        $set fixed       20

 $if not set disaggregate $set disaggregate 1 // indicator for tighter bigM constraint

 $ife %store%<=%warehouse% $abort Increase number of stores (>%warehouse)


 set res respond codes  / 0 Normal

                          1 License Error

                          2 No solution

                          3 Other Error   /

     ares(res)          / 3 /;


 Sets Warehouse  /w1*w%warehouse% /

      Store      /s1*s%store%     /

 Alias (Warehouse,w), (Store,s);

 Scalar

      fixed        fixed cost for opening a warehouse / %fixed% /

 Parameter

      capacity(WareHouse)

      supplyCost(Store,Warehouse);


 $eval storeDIVwarehouse trunc(card(store)/card(warehouse))

 capacity(w)     =   %storeDIVwarehouse% + mod(ord(w),%storeDIVwarehouse%);

 supplyCost(s,w) = 1+mod(ord(s)+10*ord(w), 100);


 Variables

     open(Warehouse)

     supply(Store,Warehouse)

     obj;

 Binary variables open, supply;


 Equations

     defobj

     oneWarehouse(s)

     defopen(w);


 defobj..  obj =e= sum(w, fixed*open(w)) + sum((w,s), supplyCost(s,w)*supply(s,w));


 oneWarehouse(s).. sum(w, supply(s,w)) =e= 1;


 defopen(w)..      sum(s, supply(s,w)) =l= open(w)*capacity(w);


 $ifthen %disaggregate%==1

 Equations

      defopen2(s,w);

 defopen2(s,w).. supply(s,w) =l= open(w);

 $endif


 model distrib /all/;

 solve distrib min obj using mip;


 $macro setResult(n) option clear=ares; ares(n) = yes;

 if (distrib.modelstat=%ModelStat.LicensingProblem% or

     distrib.solvestat=%Solvestat.LicensingProblems%,

   setResult('1');

   abort 'License Error';

 );

 if (distrib.solvestat<>%SolveStat.NormalCompletion% or

     distrib.modelstat<>%ModelStat.Optimal% and

     distrib.modelstat<>%ModelStat.IntegerSolution%,

   setResult('2');

   abort 'No solution';

 );

 setResult('0');

 ";


             return model;

         }

     }

 }