Merge branch 'daniel-coeff' into 'master'

adding a method to get the coefficient of the variable in the objective function.



See merge request !2

src/main/java/edu/illinois/cs/cogcomp/infer/ilp/BeamSearch.java

@@ -148,6 +148,11 @@ public class BeamSearch implements ILPSolver {
 		return this.objectiveValue;
 	}
 
+	@Override
+	public double objectiveCoeff(int index) {
+		return scores.get(index)[0];
+	}
+
 	public void reset() {
 		this.constraints = new ArrayList<ILPConstraint>();
 		this.scores = new ArrayList<double[]>();

src/main/java/edu/illinois/cs/cogcomp/infer/ilp/GurobiHook.java

@@ -470,6 +470,11 @@ public class GurobiHook implements ILPSolver {
         return 0;
     }
 
+    @Override
+    public double objectiveCoeff(int index) {
+        return 0;
+    }
+
 
     /**
      * Given an array of variable indexes, this method returns the corresponding Gurobi variable

src/main/java/edu/illinois/cs/cogcomp/infer/ilp/ILPSolver.java

@@ -161,6 +161,11 @@ public interface ILPSolver {
     public double objectiveValue();
 
 
+    /**
+     * The coefficient of the variable in the objective function.
+     */
+    public double objectiveCoeff(int index);
+
     /**
      * This method clears the all constraints and variables out of the ILP solver's problem
      * representation, bringing the <code>ILPSolver</code> instance back to the state it was in when

src/main/java/edu/illinois/cs/cogcomp/infer/ilp/JLISCuttingPlaneILPSolverGurobi.java

@@ -137,6 +137,11 @@ public class JLISCuttingPlaneILPSolverGurobi implements ILPSolver {
         return baseSolver.objectiveValue();
     }
 
+    @Override
+    public double objectiveCoeff(int index) {
+        return 0;
+    }
+
     public void reset() {
 
         baseSolver.reset();

src/main/java/edu/illinois/cs/cogcomp/infer/ilp/OJalgoHook.java

@@ -21,9 +21,6 @@ public class OJalgoHook implements ILPSolver {
 
     private ExpressionsBasedModel model = new ExpressionsBasedModel();
 
-    private String nameOfObjectiveExpression = "objective";
-    private Expression objectiveFunction =  model.getObjectiveExpression();
-
     // Internal flag for keeping optimization state
     private boolean minimize = true;
 
@@ -301,6 +298,11 @@ public class OJalgoHook implements ILPSolver {
         return result.getValue();
     }
 
+    @Override
+    public double objectiveCoeff(int index) {
+        return model.getVariable(index).getContributionWeight().doubleValue();
+    }
+
     public void reset() {
         if(log)
             System.out.println("OJalgoHook: reset()");