apis/examples_dotnet/Transport10_8cs_source.html

using System;

 using System.Collections.Generic;

 using System.Linq;

 using System.Text;

 using Excel = Microsoft.Office.Interop.Excel;

 using GAMS;

 using System.Diagnostics;

 using System.IO;


 namespace TransportSeq

 {

     class Transport10

     {

         static void Main(string[] args)

         {

             GAMSWorkspace ws;

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

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

             else

                 ws = new GAMSWorkspace();


             // Reading input data from workbook

             var excelApp = new Excel.Application();

             Excel.Workbook wb = excelApp.Workbooks.Open(Path.Combine(ws.SystemDirectory, @"apifiles/Data/transport.xlsx"));


             Excel.Range range;


             Excel.Worksheet capacity = (Excel.Worksheet)wb.Worksheets.get_Item("capacity");

             range = capacity.UsedRange;

             Array capacityData = (Array)range.Cells.Value;

             int iCount = capacity.UsedRange.Columns.Count;


             Excel.Worksheet demand = (Excel.Worksheet)wb.Worksheets.get_Item("demand");

             range = demand.UsedRange;

             Array demandData = (Array)range.Cells.Value;

             int jCount = range.Columns.Count;


             Excel.Worksheet distance = (Excel.Worksheet)wb.Worksheets.get_Item("distance");

             range = distance.UsedRange;

             Array distanceData = (Array)range.Cells.Value;


             // number of markets/plants have to be the same in all spreadsheets

             Debug.Assert((range.Columns.Count - 1) == jCount && (range.Rows.Count - 1) == iCount,

                          "Size of the spreadsheets doesn't match");

             wb.Close();


             // Creating the GAMSDatabase and fill with the workbook data

             GAMSDatabase db = ws.AddDatabase();


             GAMSSet i = db.AddSet("i", 1, "Plants");

             GAMSSet j = db.AddSet("j", 1, "Markets");

             GAMSParameter capacityParam = db.AddParameter("a", "Capacity", i);

             GAMSParameter demandParam = db.AddParameter("b", "Demand", j);

             GAMSParameter distanceParam = db.AddParameter("d", "Distance", i, j);


             for (int ic = 1; ic <= iCount; ic++)

             {

                 i.AddRecord((string)capacityData.GetValue(1, ic));

                 capacityParam.AddRecord((string)capacityData.GetValue(1, ic)).Value = (double)capacityData.GetValue(2, ic);

             }

             for (int jc = 1; jc <= jCount; jc++)

             {

                 j.AddRecord((string)demandData.GetValue(1, jc));

                 demandParam.AddRecord((string)demandData.GetValue(1, jc)).Value = (double)demandData.GetValue(2, jc);

                 for (int ic = 1; ic <= iCount; ic++)

                 {

                     distanceParam.AddRecord((string)distanceData.GetValue(ic + 1, 1), (string)distanceData.GetValue(1, jc + 1)).Value = (double)distanceData.GetValue(ic + 1, jc + 1);

                 }

             }


             // Create and run the GAMSJob

             using (GAMSOptions opt = ws.AddOptions())

             {

                 GAMSJob t10 = ws.AddJobFromString(GetModelText());

                 opt.Defines.Add("gdxincname", db.Name);

                 opt.AllModelTypes = "xpress";

                 t10.Run(opt, db);

                 foreach (GAMSVariableRecord rec in t10.OutDB.GetVariable("x"))

                     Console.WriteLine("x(" + rec.Key(0) + "," + rec.Key(1) + "): level=" + rec.Level + " marginal=" + rec.Marginal);

             }

         }


         static String GetModelText()

         {

             String model = @"

   Sets

        i   canning plants

        j   markets


   Parameters

        a(i)   capacity of plant i in cases

        b(j)   demand at market j in cases

        d(i,j) distance in thousands of miles

   Scalar f  freight in dollars per case per thousand miles /90/;


 $if not set gdxincname $abort 'no include file name for data file provided'

 $gdxin %gdxincname%

 $load i j a b d

 $gdxin


   Parameter c(i,j)  transport cost in thousands of dollars per case ;


             c(i,j) = f * d(i,j) / 1000 ;


   Variables

        x(i,j)  shipment quantities in cases

        z       total transportation costs in thousands of dollars ;


   Positive Variable x ;


   Equations

        cost        define objective function

        supply(i)   observe supply limit at plant i

        demand(j)   satisfy demand at market j ;


   cost ..        z  =e=  sum((i,j), c(i,j)*x(i,j)) ;


   supply(i) ..   sum(j, x(i,j))  =l=  a(i) ;


   demand(j) ..   sum(i, x(i,j))  =g=  b(j) ;


   Model transport /all/ ;


   Solve transport using lp minimizing z ;


   Display x.l, x.m ;

 ";


             return model;

         }

     }

 }