diff --git a/DAS/simulator.py b/DAS/simulator.py
index c58b20f..5aac495 100644
--- a/DAS/simulator.py
+++ b/DAS/simulator.py
@@ -61,8 +61,10 @@ class Simulator:
                     j = i - int(heavyVal/self.shape.vpn2)
                     start = offset+(  j  *self.shape.chi)
                     end   = offset+((j+1)*self.shape.chi)
-                r =    rows[start:end]
-                c = columns[start:end]
+                r = list(set(rows[start:end]))
+                c = list(set(columns[start:end]))
+                r.sort()
+                c.sort()
                 val = Validator(i, int(not i!=0), self.logger, self.shape, r, c)
             else:
                 val = Validator(i, int(not i!=0), self.logger, self.shape)
diff --git a/DAS/validator.py b/DAS/validator.py
index 32ef149..49165a0 100644
--- a/DAS/validator.py
+++ b/DAS/validator.py
@@ -69,8 +69,8 @@ class Validator:
                 #    random.seed(self.ID)
                 self.nodeClass = 1 if (self.ID <= shape.numberNodes * shape.class1ratio) else 2
                 self.vpn = self.shape.vpn1 if (self.nodeClass == 1) else self.shape.vpn2
-                self.rowIDs = set(rows) if rows else unionOfSamples(range(self.shape.blockSize), self.shape.chi, self.vpn)
-                self.columnIDs = set(columns) if columns else unionOfSamples(range(self.shape.blockSize), self.shape.chi, self.vpn)
+                self.rowIDs = rows if rows else unionOfSamples(range(self.shape.blockSize), self.shape.chi, self.vpn)
+                self.columnIDs = columns if columns else unionOfSamples(range(self.shape.blockSize), self.shape.chi, self.vpn)
         self.rowNeighbors = collections.defaultdict(dict)
         self.columnNeighbors = collections.defaultdict(dict)