diff --git a/examples/Pose3SLAMExample_changeKeys.cpp b/examples/Pose3SLAMExample_changeKeys.cpp
index 1e28c2097..ae4ee5a8c 100644
--- a/examples/Pose3SLAMExample_changeKeys.cpp
+++ b/examples/Pose3SLAMExample_changeKeys.cpp
@@ -12,7 +12,7 @@
 /**
  * @file Pose3SLAMExample_initializePose3.cpp
  * @brief A 3D Pose SLAM example that reads input from g2o, and initializes the Pose3 using InitializePose3
- * Syntax for the script is ./Pose3SLAMExample_initializePose3 input.g2o output.g2o rewritted.g2o
+ * Syntax for the script is ./Pose3SLAMExample_changeKeys input.g2o rewritted.g2o
  * @date Aug 25, 2014
  * @author Luca Carlone
  */
@@ -40,9 +40,15 @@ int main(const int argc, const char *argv[]) {
   bool is3D = true;
   boost::tie(graph, initial) = readG2o(g2oFile, is3D);
 
+  bool add = false;
   Key firstKey = 8646911284551352320;
 
   std::cout << "Using reference key: " <<  firstKey  << std::endl;
+  if(add)
+    std::cout << "adding key "  << std::endl;
+  else
+    std::cout << "subtracting key "  << std::endl;
+
 
   if (argc < 3) {
     std::cout << "Please provide output file to write "   << std::endl;
@@ -52,7 +58,12 @@ int main(const int argc, const char *argv[]) {
     // Additional: rewrite input with simplified keys 0,1,...
     Values simpleInitial;
     BOOST_FOREACH(const Values::ConstKeyValuePair& key_value, *initial) {
-      Key key = key_value.key + firstKey;
+      Key key;
+      if(add)
+        key = key_value.key + firstKey;
+      else
+        key = key_value.key - firstKey;
+
       simpleInitial.insert(key, initial->at(key_value.key));
     }
     NonlinearFactorGraph simpleGraph;
@@ -60,8 +71,14 @@ int main(const int argc, const char *argv[]) {
       boost::shared_ptr<BetweenFactor<Pose3> > pose3Between =
           boost::dynamic_pointer_cast<BetweenFactor<Pose3> >(factor);
       if (pose3Between){
-        Key key1 = pose3Between->key1() + firstKey;
-        Key key2 = pose3Between->key2() + firstKey;
+        Key key1, key2;
+        if(add){
+          key1 = pose3Between->key1() + firstKey;
+          key2 = pose3Between->key2() + firstKey;
+        }else{
+          key1 = pose3Between->key1() - firstKey;
+          key2 = pose3Between->key2() - firstKey;
+        }
         NonlinearFactor::shared_ptr simpleFactor(
             new BetweenFactor<Pose3>(key1, key2, pose3Between->measured(), pose3Between->get_noiseModel()));
         simpleGraph.add(simpleFactor);
diff --git a/examples/Pose3SLAMExample_initializePose3Chordal.cpp b/examples/Pose3SLAMExample_initializePose3Chordal.cpp
index e52534b93..afc66ea1e 100644
--- a/examples/Pose3SLAMExample_initializePose3Chordal.cpp
+++ b/examples/Pose3SLAMExample_initializePose3Chordal.cpp
@@ -63,31 +63,6 @@ int main(const int argc, const char *argv[]) {
     std::cout << "Writing results to file: " << outputFile  << std::endl;
     writeG2o(*graph, initialization, outputFile);
     std::cout << "done! " << std::endl;
-
-    // This should be deleted: only for debug
-    //    if (argc == 4){
-    //      const string inputFileRewritten = argv[3];
-    //      std::cout << "Rewriting input to file: " << inputFileRewritten << std::endl;
-    //      // Additional: rewrite input with simplified keys 0,1,...
-    //      Values simpleInitial;
-    //      BOOST_FOREACH(const Values::ConstKeyValuePair& key_value, *initial) {
-    //        Key key = key_value.key - firstKey;
-    //        simpleInitial.insert(key, initial->at(key_value.key));
-    //      }
-    //      NonlinearFactorGraph simpleGraph;
-    //      BOOST_FOREACH(const boost::shared_ptr<NonlinearFactor>& factor, *graph) {
-    //        boost::shared_ptr<BetweenFactor<Pose3> > pose3Between =
-    //            boost::dynamic_pointer_cast<BetweenFactor<Pose3> >(factor);
-    //        if (pose3Between){
-    //          Key key1 = pose3Between->key1() - firstKey;
-    //          Key key2 = pose3Between->key2() - firstKey;
-    //          NonlinearFactor::shared_ptr simpleFactor(
-    //              new BetweenFactor<Pose3>(key1, key2, pose3Between->measured(), pose3Between->get_noiseModel()));
-    //          simpleGraph.add(simpleFactor);
-    //        }
-    //      }
-    //      writeG2o(simpleGraph, simpleInitial, inputFileRewritten);
-    //    }
   }
   return 0;
 }
diff --git a/examples/Pose3SLAMExample_initializePose3Gradient.cpp b/examples/Pose3SLAMExample_initializePose3Gradient.cpp
index 898986b0a..9dc410692 100644
--- a/examples/Pose3SLAMExample_initializePose3Gradient.cpp
+++ b/examples/Pose3SLAMExample_initializePose3Gradient.cpp
@@ -43,7 +43,7 @@ int main(const int argc, const char *argv[]) {
   // Add prior on the first key
   NonlinearFactorGraph graphWithPrior = *graph;
   noiseModel::Diagonal::shared_ptr priorModel = //
-      noiseModel::Diagonal::Variances((Vector(6) << 0.1, 0.1, 0.1, 0.01, 0.01, 0.01));
+      noiseModel::Diagonal::Variances((Vector(6) << 1e-6, 1e-6, 1e-6, 1e-4, 1e-4, 1e-4));
   Key firstKey = 0;
   BOOST_FOREACH(const Values::ConstKeyValuePair& key_value, *initial) {
     std::cout << "Adding prior to g2o file " << std::endl;