diff --git a/gtsam/slam/RegularHessianFactor.h b/gtsam/slam/RegularHessianFactor.h
index c272eac8e..5765f67fd 100644
--- a/gtsam/slam/RegularHessianFactor.h
+++ b/gtsam/slam/RegularHessianFactor.h
@@ -10,10 +10,10 @@
  * -------------------------------------------------------------------------- */
 
 /**
- * @file    RegularHessianFactor.h
- * @brief   HessianFactor class with constant sized blcoks
- * @author  Richard Roberts
- * @date    Dec 8, 2010
+ * @file   RegularHessianFactor.h
+ * @brief  HessianFactor class with constant sized blocks
+ * @author Sungtae An
+ * @date   March 2014
  */
 
 #pragma once
@@ -29,8 +29,10 @@ class RegularHessianFactor: public HessianFactor {
 
 private:
 
-  typedef Eigen::Matrix<double, D, D> MatrixDD; // camera hessian block
-  typedef Eigen::Matrix<double, D, 1> VectorD;
+  // Use Eigen magic to access raw memory
+  typedef Eigen::Matrix<double, D, 1> DVector;
+  typedef Eigen::Map<DVector> DMap;
+  typedef Eigen::Map<const DVector> ConstDMap;
 
 public:
 
@@ -61,7 +63,6 @@ public:
   }
 
   // Scratch space for multiplyHessianAdd
-  typedef Eigen::Matrix<double, D, 1> DVector;
   mutable std::vector<DVector> y;
 
   /** y += alpha * A'*A*x */
@@ -78,9 +79,6 @@ public:
     BOOST_FOREACH(DVector & yi, y)
       yi.setZero();
 
-    typedef Eigen::Map<DVector> DMap;
-    typedef Eigen::Map<const DVector> ConstDMap;
-
     // Accessing the VectorValues one by one is expensive
     // So we will loop over columns to access x only once per column
     // And fill the above temporary y values, to be added into yvalues after
@@ -109,11 +107,6 @@ public:
   void multiplyHessianAdd(double alpha, const double* x, double* yvalues,
       std::vector<size_t> offsets) const {
 
-    // Use eigen magic to access raw memory
-    typedef Eigen::Matrix<double, Eigen::Dynamic, 1> DVector;
-    typedef Eigen::Map<DVector> DMap;
-    typedef Eigen::Map<const DVector> ConstDMap;
-
     // Create a vector of temporary y values, corresponding to rows i
     std::vector<Vector> y;
     y.reserve(size());
@@ -149,10 +142,6 @@ public:
   /** Return the diagonal of the Hessian for this factor (raw memory version) */
   virtual void hessianDiagonal(double* d) const {
 
-    // Use eigen magic to access raw memory
-    typedef Eigen::Matrix<double, D, 1> DVector;
-    typedef Eigen::Map<DVector> DMap;
-
     // Loop over all variables in the factor
     for (DenseIndex pos = 0; pos < (DenseIndex) size(); ++pos) {
       Key j = keys_[pos];
@@ -165,22 +154,19 @@ public:
   /// Add gradient at zero to d TODO: is it really the goal to add ??
   virtual void gradientAtZero(double* d) const {
 
-    // Use eigen magic to access raw memory
-    typedef Eigen::Matrix<double, D, 1> DVector;
-    typedef Eigen::Map<DVector> DMap;
-
     // Loop over all variables in the factor
     for (DenseIndex pos = 0; pos < (DenseIndex) size(); ++pos) {
       Key j = keys_[pos];
       // Get the diagonal block, and insert its diagonal
-      VectorD dj = -info_(pos, size()).knownOffDiagonal();
+      DVector dj = -info_(pos, size()).knownOffDiagonal();
       DMap(d + D * j) += dj;
     }
   }
 
   /* ************************************************************************* */
 
-}; // end class RegularHessianFactor
+};
+// end class RegularHessianFactor
 
 // traits
 template<size_t D> struct traits<RegularHessianFactor<D> > : public Testable<