no message

GAMS/IntExtOpt.gms

+  
+ SET crop crop types including pasture / cereals, fruits, oilcrops, starchyRoots, treenuts, vegetables, pasture /
+ SET crop_less_pasture(crop) arable crops types includes treenuts but not pasture / cereals, fruits, oilcrops, starchyRoots, treenuts, vegetables /
+ SET feed_crop(crop)  / cereals, oilcrops /
+ SET landuse land use type / cropland, pasture /
+     
+ PARAMETER previous_area(landuse) areas for previous timestep in ha       
+ PARAMETER demand(crop) yield in t per ha
+ PARAMETER yield_ref(crop) yield in t per ha
+ 
+$gdxin %gdxincname%
+$load previous_area, demand, yield_ref
+$gdxin
+       
+                                  
+ PARAMETER
+       feedEnergy(crop) energy from feed in MJ per t
+         /    cereals       1
+              oilcrops      1.5
+              pasture       0.4
+              / ;
+              
+ SCALAR meatDemand /200/;
+ SCALAR meatEfficency /0.1/;
+ SCALAR maxLandUseChange /0.1/;   
+              
+ VARIABLES
+       area(crop) total area for each crop
+       feedArea(crop)  area used for feed for each crop
+       intensity(crop)  intensity for each crop
+       yield(crop) energy per area for each crop
+       unit_energy(crop) energy per area for each crop
+       energy      total input energy
+       ;
+       
+ POSITIVE VARIABLE area, intensity, feedArea;
+  
+ EQUATIONS
+       UNIT_ENERGY_EQ(crop) energy per area
+       YIELD_EQ(crop) yield given chosen intensity
+       CROP_DEMAND_CONSTRAINT(crop_less_pasture) satisfy demand for crop 
+       MEAT_DEMAND_CONSTRAINT satisfy demand for crop 
+       INTENSITY_CONSTRAINT(crop) intensity constraint 
+       CROPLAND_CHANGE_CONSTRAINT constraint on the rate of land use change 
+       PASTURE_CHANGE_CONSTRAINT constraint on the rate of land use change 
+       AGRI_LAND_CHANGE_CONSTRAINT constraint expansion of agricultural land
+       ENERGY_EQ define objective function;
+       
+ UNIT_ENERGY_EQ(crop) .. unit_energy(crop) =E= intensity(crop) + intensity(crop) / 2 * intensity(crop) / 8;
+  
+ YIELD_EQ(crop) .. yield(crop) =E= yield_ref(crop) * intensity(crop);
+  
+ CROP_DEMAND_CONSTRAINT(crop_less_pasture) .. (area(crop_less_pasture) - feedArea(crop_less_pasture)) * yield(crop_less_pasture) =G= demand(crop_less_pasture);
+  
+ MEAT_DEMAND_CONSTRAINT .. meatEfficency*sum(feed_crop, feedEnergy(feed_crop) * feedArea(feed_crop) * yield(feed_crop)) + 
+  			feedEnergy('pasture') * area('pasture') * yield('pasture') =G= meatDemand;
+  
+ INTENSITY_CONSTRAINT(crop) .. intensity(crop) =G= 1;
+  
+ CROPLAND_CHANGE_CONSTRAINT .. abs(sum(crop_less_pasture, area(crop_less_pasture))/previous_area('cropland') - 1) =L= maxLandUseChange;
+  
+ PASTURE_CHANGE_CONSTRAINT ..  abs(area('pasture')/previous_area('pasture') - 1) =L= maxLandUseChange;
+  
+ AGRI_LAND_CHANGE_CONSTRAINT .. abs(sum(crop, area(crop)) / sum(landuse, previous_area(landuse)) - 1) =L= maxLandUseChange;
+  
+ ENERGY_EQ .. energy =E= SUM(crop, area(crop)*unit_energy(crop));
+  
+ MODEL LAND_USE /ALL/ ;
+ SOLVE LAND_USE USING DNLP MINIMIZING energy;
+

src/ac/ed/lurg/GamsTest.java

@@ -15,15 +15,13 @@ import com.gams.api.GAMSWorkspaceInfo;
 
 public class GamsTest {
 	
+	private final static String WORKING_DIR = "/Users/peteralexander/Documents/R_Workspace/tempDir";
+	
     public static void main(String[] args)  {
-
-        // create GAMSWorkspace "ws" with default working directory 
-        // (the directory named with current date and time under System.getProperty("java.io.tmpdir"))
-    	System.out.println(System.getProperty("user.dir"));
-        File workingDirectory = new File(System.getProperty("user.dir"), "GamsTest");
+    	
+    	File workingDirectory = new File(WORKING_DIR, "GamsTest");
         workingDirectory.mkdir();
 
-        // create a workspace
         GAMSWorkspaceInfo  wsInfo  = new GAMSWorkspaceInfo();
         wsInfo.setWorkingDirectory(workingDirectory.getAbsolutePath());
 
@@ -59,7 +57,6 @@ public class GamsTest {
         }
 
         // add a database and add input data into the database
-
         GAMSParameter a = db.addParameter("previous_area", 1, "previous area");
         for(String c : previous_area.keySet())
             a.addRecord(c).setValue(previous_area.get(c));
@@ -73,7 +70,7 @@ public class GamsTest {
             y.addRecord(c).setValue(yield_ref.get(c));
 
         // create GAMSJob "t2" from the "model" string variable
-        GAMSJob t2 = ws.addJobFromFile("/Users/peteralexander/Documents/R_Workspace/landalloc/GAMS/IntExtOpt.gms");
+        GAMSJob t2 = ws.addJobFromFile("/Users/peteralexander/Documents/R_Workspace/UNPLUM/GAMS/IntExtOpt.gms");
         GAMSOptions opt = ws.addOptions();
 
         System.out.println(db.getName());
@@ -90,8 +87,6 @@ public class GamsTest {
 
         // cleanup GAMSWorkspace's working directory
         cleanup(ws.workingDirectory());
-        // terminate program
-        System.exit(0);
    }
 
    static void cleanup(String directory)  {