new example of a simple buffer allocation problem added

dream/simulation/Examples/BufferAllocation.py

+from dream.simulation.imports import Machine, Source, Exit, Part, Queue, NonStarvingEntry
+from dream.simulation.Globals import runSimulation
+
+#define the objects of the model
+NS=NonStarvingEntry('NS1','Entry',entityData={'_class':'Dream.Part'})
+M1=Machine('M1','Machine1', processingTime={'Exp':{'mean':1}})
+Q2=Queue('Q2','Queue2')
+M2=Machine('M2','Machine2', processingTime={'Exp':{'mean':3}})
+Q3=Queue('Q3','Queue3')
+M3=Machine('M3','Machine3', processingTime={'Exp':{'mean':5}})
+E=Exit('E1','Exit')  
+
+
+#define predecessors and successors for the objects    
+NS.defineRouting(successorList=[M1])
+M1.defineRouting(predecessorList=[NS],successorList=[Q2])
+Q2.defineRouting(predecessorList=[M1],successorList=[M2])
+M2.defineRouting(predecessorList=[Q2],successorList=[Q3])
+Q3.defineRouting(predecessorList=[M2],successorList=[M3])
+M3.defineRouting(predecessorList=[Q3],successorList=[E])
+E.defineRouting(predecessorList=[M3])
+
+def main(test=0):
+    # add all the objects in a list
+    objectList=[NS,M1,M2,M3,Q2,Q3,E]  
+    # set the length of the experiment  
+    maxSimTime=480
+    
+    solutionList=[]
+    
+    for i in range(1,10):
+        Q2.capacity=i
+        Q3.capacity=10-i
+        # call the runSimulation giving the objects and the length of the experiment
+        runSimulation(objectList, maxSimTime,numberOfReplications=10)
+    
+        # return results for the test
+        if test:
+            return {"parts": E.numOfExits}
+       
+        solutionList.append({
+                             "Q2":Q2.capacity,
+                             "Q3":Q3.capacity,
+                             "throughput":sum(E.Exits)/float(len(E.Exits))
+                             }
+                            )
+        E.Exits=[]
+    solutionList.sort(key=lambda x: x.get("throughput",0), reverse=True)
+    print "the best allocation is for Q2",solutionList[0]['Q2'],"units and Q3",solutionList[0]['Q2'],\
+            "units, with a predicted throughput of",solutionList[0]['throughput']
+
+if __name__ == '__main__':
+    main()