diff --git a/resources/MatlabInterface/@JEInterface/JEInterface.m b/resources/MatlabInterface/@JEInterface/JEInterface.m
index 3f3015a9..2cb304f2 100644
--- a/resources/MatlabInterface/@JEInterface/JEInterface.m
+++ b/resources/MatlabInterface/@JEInterface/JEInterface.m
@@ -1,12 +1,14 @@
-function int = JEInterface(fhandle, range, varargin)
+function int = JEInterface(fhandle, datatype, range, varargin)
 % EvA2 Interface for Matlab
-%       JEInterface(fhandle, range)
-%       JEInterface(fhandle, range, initRange)
-%       JEInterface(fhandle, range, initRange, defaultargs)
-%       JEInterface(fhandle, range, initRange, defaultargs, options...)
+%       JEInterface(fhandle, datatype, range)
+%       JEInterface(fhandle, datatype, range, initRange)
+%       JEInterface(fhandle, datatype, range, initRange, defaultargs)
+%       JEInterface(fhandle, datatype, range, initRange, defaultargs, options...)
 %
 % Arguments: 
 %   fhandle: a function handle defining the optimization target.
+%   datatype: symbol 'int', 'double', or 'binary' denoting the problem data
+%       type
 %   range: a 2 x dim array defining the solution subspace with lower and
 %      upper bounds; or a scalar defining the bitwidth for binary
 %      problems.
@@ -52,11 +54,22 @@ int.mediator = '';
 int.optParams = [];
 int.optParamValues = [];
 int.hexMask=hex2dec('ffffffff');
+int.dataType=''; % to be set later!
 
 if (isa(fhandle, 'function_handle'))
     int.f = fhandle;
 else
-    error('Wrong second argument type, expected function_handle');
+    error('Wrong first argument type, expected function_handle');
+end
+
+if (strcmp(datatype,'double'))
+    int.dataType=eva2.server.go.problems.MatlabProblemDataTypeEnum.typeDouble;
+elseif strcmp(datatype, 'int')
+    int.dataType=eva2.server.go.problems.MatlabProblemDataTypeEnum.typeInteger;
+elseif strcmp(datatype, 'binary')
+    int.dataType=eva2.server.go.problems.MatlabProblemDataTypeEnum.typeBinary;
+else
+    error('Invalid data type, select double, int, or binary!');
 end
 
 disp('Setting up JEInterface...');
@@ -79,7 +92,7 @@ end
 int = class(int,'JEInterface');
 int.opts = makeOptions(int);
 
-if (nargin>2)
+if (nargin>3)
     int.initialRange=varargin{1};
     
     if (isa(varargin{1}, 'double') && (size(varargin{1},1) == 2))
@@ -91,15 +104,15 @@ if (nargin>2)
         disp(s);
     end
     
-    if (nargin>3)
+    if (nargin>4)
         int.args = varargin{2};
         disp('Fitness function argument: '); disp(int.args);
-        if (nargin > 4)
-            if (rem(nargin,2)==1)
+        if (nargin > 5)
+            if (rem(nargin,2)==0)
                 error('Invalid number of arguments!');
             end
             disp('Reading options:');
-            for i=3:2:nargin-2
+            for i=3:2:nargin-3
                 int=setOpt(int, varargin{i}, varargin{i+1});
             end
         end
@@ -107,11 +120,15 @@ if (nargin>2)
 end  
 display(getOptions(int));
 % finally create the java object
-if (isempty(int.initialRange))
-    int.mp = eva2.server.go.problems.MatlabProblem(int.dim, int.range);
+if (isempty(int.initialRange)) % binary case
+    int.mp = eva2.server.go.problems.MatlabProblem(int.dim, int.dataType, int.range);
 else
-    if (isempty(int.range) || eq(size(int.range), size(int.initialRange)))
-        int.mp = eva2.server.go.problems.MatlabProblem(int.dim, int.range, int.initialRange);
+%     size(int.range);
+%     size(int.initialRange);
+%     eq(size(int.range), size(int.initialRange))
+%     disp('-------');
+    if (isempty(int.range) || (sum(eq(size(int.range), size(int.initialRange)))==2))
+        int.mp = eva2.server.go.problems.MatlabProblem(int.dim, int.dataType, int.range, int.initialRange);
         %int.mp.getIndividualTemplate().setMutationOperator( ...
         %    eva2.server.go.operators.mutation.MutateEAMixer(eva2.server.go.operators.mutation.MutateGASwapBits, eva2.server.go.operators.mutation.MutateGAUniform));
     else 
diff --git a/resources/MatlabInterface/@JEInterface/testEvalFunc.m b/resources/MatlabInterface/@JEInterface/testEvalFunc.m
index b085b15e..8210c4a9 100644
--- a/resources/MatlabInterface/@JEInterface/testEvalFunc.m
+++ b/resources/MatlabInterface/@JEInterface/testEvalFunc.m
@@ -2,7 +2,7 @@ function testEvalFunc(int)
 % Test the fitness function output format.
 wordwidth=32;
 
-if (isempty(int.range))
+if (strcmp(int.dataType,eva2.server.go.problems.MatlabProblemDataTypeEnum.typeBinary))
     % binary problem
     s=sprintf('Binary problem of bitwidth %d', int.dim);
     disp(s);
@@ -13,7 +13,7 @@ if (isempty(int.range))
     %x(numInts)=bitshift(x(numInts),-overheadBits); % shift right by overhead
     bs=eva2.tools.math.RNG.randomBitSet(0.5, int.dim);
     x=convertUnsignedJE(int, bs);
-else
+elseif strcmp(int.dataType,eva2.server.go.problems.MatlabProblemDataTypeEnum.typeDouble)
     % double problem
     x=rand(1, int.dim);
     s=sprintf('Real valued problem in %d dimensions and range %s ', int.dim, mat2str(int.range));
@@ -21,8 +21,16 @@ else
     for i=1:int.dim
         x(i)=int.range(i,1)+x(i)*(int.range(i,2)-int.range(i,1));
     end
+elseif strcmp(int.dataType,eva2.server.go.problems.MatlabProblemDataTypeEnum.typeInteger)
+    % integer problem
+    s=sprintf('Real valued problem in %d dimensions and range %s ', int.dim, mat2str(int.range));
+    disp(s);
+    size(int.range)
+    %x=int.range(1,:)+ceil(rand(1,int.dim).*int.range(2,:)-int.range(1,:));
+    x=(int.range(:,1)+ceil(rand(int.dim,1).*int.range(:,2)-int.range(:,1)))';
+else 
+    error('Invalid data type in testEvalFunc.m!'); 
 end
-
 if (isempty(int.range))
     msg=sprintf('\nTesting value: %d, bin.: %s', x, dec2bin(x, int.dim));
 else
diff --git a/src/eva2/server/go/problems/MatlabEvalMediator.java b/src/eva2/server/go/problems/MatlabEvalMediator.java
index af2f3bff..d0f7b031 100644
--- a/src/eva2/server/go/problems/MatlabEvalMediator.java
+++ b/src/eva2/server/go/problems/MatlabEvalMediator.java
@@ -233,17 +233,22 @@ public class MatlabEvalMediator {
 	}
 	
 	void setSolution(Object sol) {
-		//System.out.println("setting Sol");
+//		System.err.println("setting obj Sol " + BeanInspector.toString(sol));
 		optSolution = sol;
 	}
 	
 	void setSolutionSet(double[][] solSet) {
-//		System.err.println("setting SolSet " + ((solSet != null) ? solSet.length : 0));
+//		System.err.println("setting dbl SolSet " + ((solSet != null) ? solSet.length : 0));
 		optSolSet = solSet;
 	}
 	
 	void setSolutionSet(BitSet[] solSet) {
-//		System.err.println("setting SolSet " + ((solSet != null) ? solSet.length : 0));
+//		System.err.println("setting bs SolSet " + ((solSet != null) ? solSet.length : 0));
+		optSolSet = solSet;
+	}
+	
+	void setSolutionSet(int[][] solSet) {
+//		System.err.println("setting int SolSet " + ((solSet != null) ? solSet.length : 0));
 		optSolSet = solSet;
 	}
 	
@@ -252,7 +257,7 @@ public class MatlabEvalMediator {
 	 * @return
 	 */
 	public Object getSolution() {
-//		System.err.println("getting Sol");
+//		System.err.println("getting Sol " + BeanInspector.toString(optSolution));
 		return optSolution;
 	}
 	
diff --git a/src/eva2/server/go/problems/MatlabProblem.java b/src/eva2/server/go/problems/MatlabProblem.java
index 42c7d002..5abec10b 100644
--- a/src/eva2/server/go/problems/MatlabProblem.java
+++ b/src/eva2/server/go/problems/MatlabProblem.java
@@ -14,8 +14,10 @@ import eva2.server.go.PopulationInterface;
 import eva2.server.go.individuals.AbstractEAIndividual;
 import eva2.server.go.individuals.ESIndividualDoubleData;
 import eva2.server.go.individuals.GAIndividualBinaryData;
+import eva2.server.go.individuals.GIIndividualIntegerData;
 import eva2.server.go.individuals.InterfaceDataTypeBinary;
 import eva2.server.go.individuals.InterfaceDataTypeDouble;
+import eva2.server.go.individuals.InterfaceDataTypeInteger;
 import eva2.server.go.operators.postprocess.InterfacePostProcessParams;
 import eva2.server.go.operators.postprocess.PostProcess;
 import eva2.server.go.operators.postprocess.PostProcessParams;
@@ -50,16 +52,16 @@ public class MatlabProblem extends AbstractOptimizationProblem implements Interf
 //	transient PrintStream				resOutStream = null;
 	int 								verbosityLevel	= 0;
 	private MatlabEvalMediator 			handler = null;
-	private boolean isDouble = true;
+//	private boolean isDouble = true;
+	private MatlabProblemDataTypeEnum dataType = MatlabProblemDataTypeEnum.typeDouble;
 	private double[][] initialRange = null; // the initial range for double-valued problems
 
 	public static boolean hideFromGOE = true; 
-
+	
 //	transient private double[] currArray = null;
 //	private String mtCmd = null;
 
 	public MatlabProblem(MatlabProblem o) {
-//		this.matlab = o.matlab;
 		this.m_Template=null;
 		this.handler = o.handler;
 		this.runnable = o.runnable;
@@ -69,7 +71,7 @@ public class MatlabProblem extends AbstractOptimizationProblem implements Interf
 //		this.res = new ResultArr();
 //		if (o.res != null) if (o.res.get() != null) res.set(o.res.get());
 		this.range = o.range;
-		this.isDouble = o.isDouble;
+		this.dataType = o.dataType;
 		this.initialRange = o.initialRange;
 //		this.mtCmd = o.mtCmd;
 //		currArray = null;
@@ -79,61 +81,104 @@ public class MatlabProblem extends AbstractOptimizationProblem implements Interf
 		return new MatlabProblem(this);
 	}
 
+	/**
+	 * Constructor of a real valued problem.
+	 * @param dim
+	 * @param range
+	 */
+//	public MatlabProblem(int dim, double[][] range) {
+//		init(dim, ProblemDataTypeEnum.typeDouble, range, null, defTestOut);
+//	}
+	
+	/**
+	 * Constructor of a binary problem with given bit length.
+	 * @param dim
+	 */
 	public MatlabProblem(int dim) {
-		this(dim, (double[][])null);
-	}
-
-	public MatlabProblem(int dim, double[][] range) {
-		init(dim, range, null, defTestOut);
+		init(dim, MatlabProblemDataTypeEnum.typeBinary, null, null, defTestOut);
 	}
 	
-	public MatlabProblem(int dim, double[][] range, double[][] initRange) {
-		init(dim, range, initRange, defTestOut);
+	/**
+	 * Constructor of a real valued problem with initialization range.
+	 * @param dim
+	 * @param range
+	 * @param initRange
+	 */
+//	public MatlabProblem(int dim, double[][] range, double[][] initRange) {
+//		init(dim, ProblemDataTypeEnum.typeDouble, range, initRange, defTestOut);
+//	}
+
+	/**
+	 * Constructor of real or integer valued problem, the range will be converted
+	 * to integer in the latter case.
+	 * 
+	 * @param dim
+	 * @param datType
+	 * @param range
+	 */
+	public MatlabProblem(int dim, MatlabProblemDataTypeEnum datType, double[][] range) {
+		init(dim, datType, range, null, defTestOut);
+	}
+	
+	/**
+	 * Constructor of real or integer valued problem with initialization range. 
+	 * The ranges will be converted to integer in the latter case.
+	 * 
+	 * @param dim
+	 * @param datType
+	 * @param range
+	 */
+	public MatlabProblem(int dim, MatlabProblemDataTypeEnum datType, double[][] range, double[][] initRange) {
+		init(dim, datType, range, initRange, defTestOut);
 	}
 
-	public MatlabProblem(int dim, double lower, double upper) {
-		this(dim, null);
-		double[][] range = new double[dim][2];
-		for (int i=0; i<dim; i++) {
-			range[dim][0] = lower;
-			range[dim][1] = upper;
-		}
-	}
+	
+//	public MatlabProblem(int dim, double lower, double upper) {
+//		this(dim, null);
+//		double[][] range = new double[dim][2];
+//		for (int i=0; i<dim; i++) {
+//			range[dim][0] = lower;
+//			range[dim][1] = upper;
+//		}
+//	}
 
 	protected void initTemplate() {
-		if (isDouble) {
-			if (m_Template == null) m_Template         = new ESIndividualDoubleData();
+		switch (dataType) {
+		case typeDouble:
+			if (m_Template == null || !(m_Template instanceof ESIndividualDoubleData)) m_Template         = new ESIndividualDoubleData();
 			if (getProblemDimension() > 0) { // avoid evil case setting dim to 0 during object init
 				((InterfaceDataTypeDouble)this.m_Template).setDoubleDataLength(getProblemDimension());
 				((InterfaceDataTypeDouble)this.m_Template).SetDoubleRange(range);
 			}
-		} else {
+			break;
+		case typeBinary:
 			///// binary alternative
-			if (m_Template == null) m_Template         = new GAIndividualBinaryData(getProblemDimension());
-
-			///// Integer alternative
-			/*if (m_Template == null) m_Template         = new GAIndividualIntegerData();
-			int intLen = 1+((getProblemDimension()-1)/32);
-			int lastIntCodingBits = getProblemDimension()-((intLen-1)*32);
-			if (lastIntCodingBits > 32) System.err.println("ERROR in MatlabProblem:initTemplate");
-			((GAIndividualIntegerData)m_Template).setIntegerDataLength(intLen);
-			((GAIndividualIntegerData)m_Template).SetIntRange(Integer.MIN_VALUE, Integer.MAX_VALUE);
-			if (lastIntCodingBits < 32) ((GAIndividualIntegerData)m_Template).SetIntRange(intLen-1, 0, (int)Math.pow(2, lastIntCodingBits)-1);
-			*/ 			/////
-//			System.err.println("integer length is "+((GAIndividualIntegerData)m_Template).getIntegerData().length);
-//			System.err.println("Range is " + BeanInspector.toString(((GAIndividualIntegerData)m_Template).getIntRange()));
-//			m_Template         = new GAIndividualBinaryData();
-//			((GAIndividualBinaryData)m_Template).setBinaryDataLength(getProblemDimension());
+			if (m_Template == null || !(m_Template instanceof GAIndividualBinaryData)) m_Template         = new GAIndividualBinaryData(getProblemDimension());
+			break;
+		case typeInteger:
+			int[][] intRange=makeIntRange(range);
+			if (m_Template == null || !(m_Template instanceof GIIndividualIntegerData)) m_Template         = new GIIndividualIntegerData(intRange);
+			break;
 		}
 	}
 
+	private int[][] makeIntRange(double[][] r) {
+		int[][] intRange=new int[r.length][r[0].length];
+		for (int i=0; i<r.length; i++){
+			for (int j=0; j<r[0].length; j++) {
+				intRange[i][j]=(int)r[i][j];
+			}
+		}
+		return intRange;
+	}
+
 	public void setMediator(MatlabEvalMediator h) {
 		handler = h;
 		handler.setMatlabProblem(this);
 	}
 
 	public void initProblem() {
-		init(this.problemDimension, range, initialRange, defTestOut);
+		init(this.problemDimension, dataType, range, initialRange, defTestOut);
 	}
 
 	public static FitnessConvergenceTerminator makeFitConvTerm(double thresh, int stagnPeriod) {
@@ -154,7 +199,7 @@ public class MatlabProblem extends AbstractOptimizationProblem implements Interf
 	 * @param initRange
 	 * @param outFile
 	 */
-	private void init(int dim, double[][] globalRange, double[][] initRange, String outFile) {
+	private void init(int dim, MatlabProblemDataTypeEnum datType, double[][] globalRange, double[][] initRange, String outFile) {
 		this.problemDimension = dim;
 //		if ((rng != null) && (dim != rng.length)) throw new ArrayIndexOutOfBoundsException("Mismatching dimension and range!");
 		if (globalRange!=null) { // these may be Matlab objects, so I do it by foot, just to be sure not to clone them within Matlab instead of here 
@@ -173,8 +218,8 @@ public class MatlabProblem extends AbstractOptimizationProblem implements Interf
 		
 		if (Arrays.deepEquals(initialRange, range)) initialRange=null;
 		
-		if (range==null) isDouble = false;
-		else isDouble = true;
+		dataType=datType; // store the data type
+		log("### Data type is " + dataType);
 
 //		System.err.println("isDouble: " + isDouble);
 //		System.err.println("range: " + BeanInspector.toString(range));
@@ -411,34 +456,42 @@ public class MatlabProblem extends AbstractOptimizationProblem implements Interf
 
 	void exportResultPopulationToMatlab(Population pop) {
 		if ((pop != null) && (pop.size()>0)) {
-			if (isDouble) {
-				double[][] solSet = new double[pop.size()][];
+			switch(dataType) {
+			case typeDouble:
+				double[][] rsolSet = new double[pop.size()][];
 				for (int i=0; i<pop.size(); i++) {
-					solSet[i]=((InterfaceDataTypeDouble)pop.getEAIndividual(i)).getDoubleData();
+					rsolSet[i]=((InterfaceDataTypeDouble)pop.getEAIndividual(i)).getDoubleData();
 				}
-				handler.setSolutionSet(solSet);
-			} else {
-				BitSet[] solSet = new BitSet[pop.size()];
+				handler.setSolutionSet(rsolSet);
+				break;
+			case typeBinary:
+				BitSet[] bsolSet = new BitSet[pop.size()];
 				for (int i=0; i<pop.size(); i++) {
-					solSet[i]=((InterfaceDataTypeBinary)pop.getEAIndividual(i)).getBinaryData();
+					bsolSet[i]=((InterfaceDataTypeBinary)pop.getEAIndividual(i)).getBinaryData();
 				}
-				handler.setSolutionSet(solSet);
+				handler.setSolutionSet(bsolSet);
+				break;
+			case typeInteger: 
+				int[][] isolSet = new int[pop.size()][];
+				for (int i=0; i<pop.size(); i++) {
+					isolSet[i]=((InterfaceDataTypeInteger)pop.getEAIndividual(i)).getIntegerData();
+				}
+				handler.setSolutionSet(isolSet);
+				break;
 			}
 		} else {
-			if (isDouble) handler.setSolutionSet((double[][])null);
-			else handler.setSolutionSet((BitSet[])null);
+			switch(dataType) {
+			case typeDouble: handler.setSolutionSet((double[][])null); break;
+			case typeBinary: handler.setSolutionSet((BitSet[])null); break;
+			case typeInteger: handler.setSolutionSet((int[][])null); break;
+			}
 		}
 	}
 
-	void exportResultToMatlab(OptimizerRunnable runnable) {
-		if (isDouble) handler.setSolution(runnable.getDoubleSolution());
-		else handler.setSolution(runnable.getBinarySolution());
+	public void exportResultToMatlab(OptimizerRunnable runnable) {
+		handler.setSolution(getIntermediateResult());
 	}
 
-//	void exportResultToMatlab(double[] result) {
-//		handler.setSolution(result);
-//	}
-
 	/**
 	 * To be called by the executing thread to inform that the thread is finished.
 	 * We 
@@ -448,10 +501,16 @@ public class MatlabProblem extends AbstractOptimizationProblem implements Interf
 	}
 
 	public Object getIntermediateResult() {
-		if (runnable == null) return null;
-		else {
-			if (isDouble) return runnable.getDoubleSolution();
-			else return runnable.getIntegerSolution();
+		if (runnable == null) { 
+			System.err.println("Warning, runnable is null in MatlabProblem!");
+			return null;
+		} else {
+			switch(dataType) {
+			case typeDouble: return runnable.getDoubleSolution();
+			case typeBinary: return runnable.getBinarySolution();
+			case typeInteger: return runnable.getIntegerSolution();
+			default: System.err.println("Warning, incompatible data type in MatlabProblem!");return null;
+			}
 		}
 	}
 
diff --git a/src/eva2/server/go/problems/MatlabProblemDataTypeEnum.java b/src/eva2/server/go/problems/MatlabProblemDataTypeEnum.java
new file mode 100644
index 00000000..01d543cb
--- /dev/null
+++ b/src/eva2/server/go/problems/MatlabProblemDataTypeEnum.java
@@ -0,0 +1,5 @@
+package eva2.server.go.problems;
+
+public enum MatlabProblemDataTypeEnum {
+	 typeDouble, typeBinary, typeInteger;
+}