some more comments

gtsam/navigation/AHRSFactor.h

@@ -140,6 +140,7 @@ class GTSAM_EXPORT AHRSFactor: public NoiseModelFactorN<Rot3, Rot3, Vector3> {
 
 public:
 
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
   /** Shorthand for a smart pointer to a factor */
 #if !defined(_MSC_VER) && __GNUC__ == 4 && __GNUC_MINOR__ > 5

gtsam/navigation/AttitudeFactor.h

@@ -82,6 +82,7 @@ class GTSAM_EXPORT Rot3AttitudeFactor: public NoiseModelFactorN<Rot3>, public At
 
 public:
 
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
   /// shorthand for a smart pointer to a factor
   typedef boost::shared_ptr<Rot3AttitudeFactor> shared_ptr;
@@ -156,6 +157,7 @@ class GTSAM_EXPORT Pose3AttitudeFactor: public NoiseModelFactorN<Pose3>,
   typedef NoiseModelFactorN<Pose3> Base;
 
 public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
 
   /// shorthand for a smart pointer to a factor

gtsam/navigation/BarometricFactor.h

@@ -38,6 +38,7 @@ class GTSAM_EXPORT BarometricFactor : public NoiseModelFactorN<Pose3, double> {
     double nT_;  ///< Height Measurement based on a standard atmosphere
 
    public:
+    // Provide access to the Matrix& version of evaluateError:
     using Base::evaluateError;
     /// shorthand for a smart pointer to a factor
     typedef boost::shared_ptr<BarometricFactor> shared_ptr;

gtsam/navigation/GPSFactor.h

@@ -42,6 +42,7 @@ private:
 
 public:
 
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
   /// shorthand for a smart pointer to a factor
   typedef boost::shared_ptr<GPSFactor> shared_ptr;
@@ -120,6 +121,7 @@ private:
   Point3 nT_; ///< Position measurement in cartesian coordinates
 
 public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
 
   /// shorthand for a smart pointer to a factor

gtsam/navigation/ImuFactor.h

@@ -179,6 +179,7 @@ private:
   PreintegratedImuMeasurements _PIM_;
 
 public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
 
   /** Shorthand for a smart pointer to a factor */

gtsam/navigation/MagPoseFactor.h

@@ -49,6 +49,7 @@ class MagPoseFactor: public NoiseModelFactorN<POSE> {
   GTSAM_CONCEPT_POSE_TYPE(POSE)
 
  public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
 
   ~MagPoseFactor() override {}

gtsam/nonlinear/FunctorizedFactor.h

@@ -65,6 +65,7 @@ class FunctorizedFactor : public NoiseModelFactorN<T> {
   std::function<R(T, OptionalMatrixType)> func_;  ///< functor instance
 
  public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
   /** default constructor - only use for serialization */
   FunctorizedFactor() {}
@@ -166,6 +167,7 @@ class FunctorizedFactor2 : public NoiseModelFactorN<T1, T2> {
   FunctionType func_;  ///< functor instance
 
  public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
   /** default constructor - only use for serialization */
   FunctorizedFactor2() {}

gtsam/nonlinear/NonlinearEquality.h

@@ -305,6 +305,7 @@ class NonlinearEquality2 : public NoiseModelFactorN<T, T> {
 
  public:
   typedef boost::shared_ptr<NonlinearEquality2<T>> shared_ptr;
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
 
   /**

gtsam/slam/EssentialMatrixFactor.h

@@ -117,6 +117,7 @@ class EssentialMatrixFactor2
   typedef EssentialMatrixFactor2 This;
 
  public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
   /**
    *  Constructor

gtsam/slam/RotateFactor.h

@@ -74,6 +74,7 @@ class RotateDirectionsFactor: public NoiseModelFactorN<Rot3> {
   typedef RotateDirectionsFactor This;
 
 public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
 
   /// Constructor

gtsam_unstable/dynamics/IMUFactor.h

@@ -32,6 +32,7 @@ protected:
   double dt_; /// time between measurements
 
 public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
 
   /** Standard constructor */

gtsam_unstable/slam/GaussMarkov1stOrderFactor.h

@@ -53,6 +53,7 @@ private:
   Vector tau_;
 
 public:
+  // Provide access to the Matrix& version of evaluateError:
   using Base::evaluateError;
 
   // shorthand for a smart pointer to a factor

tests/simulated2D.h

@@ -133,6 +133,7 @@ namespace simulated2D {
     typedef boost::shared_ptr<GenericPrior<VALUE> > shared_ptr;
     typedef VALUE Pose; ///< shortcut to Pose type
 	
+    // Provide access to the Matrix& version of evaluateError:
     using Base::evaluateError;
 
     Pose measured_; ///< prior mean
@@ -179,6 +180,7 @@ namespace simulated2D {
     typedef boost::shared_ptr<GenericOdometry<VALUE> > shared_ptr;
     typedef VALUE Pose; ///< shortcut to Pose type
 
+    // Provide access to the Matrix& version of evaluateError:
     using Base::evaluateError;
 
     Pose measured_; ///< odometry measurement
@@ -227,6 +229,7 @@ namespace simulated2D {
     typedef POSE Pose; ///< shortcut to Pose type
     typedef LANDMARK Landmark; ///< shortcut to Landmark type
 
+    // Provide access to the Matrix& version of evaluateError:
     using Base::evaluateError;
 
     Landmark measured_; ///< Measurement