diff --git a/gtsam/linear/SharedDiagonal.h b/gtsam/linear/SharedDiagonal.h
index 8a7e101a2..193a30215 100644
--- a/gtsam/linear/SharedDiagonal.h
+++ b/gtsam/linear/SharedDiagonal.h
@@ -22,11 +22,17 @@
 
 namespace gtsam { // note, deliberately not in noiseModel namespace
 
-	// A useful convenience class to refer to a shared Diagonal model
-	// There are (somewhat dangerous) constructors from Vector and pair<size_t,double>
-	// that call Sigmas and Sigma, respectively.
+	/**
+	 * A useful convenience class to refer to a shared Diagonal model
+	 * There are (somewhat dangerous) constructors from Vector and pair<size_t,double>
+	 * that call Sigmas and Sigma, respectively.
+	 */
 	class SharedDiagonal: public noiseModel::Diagonal::shared_ptr {
 	public:
+
+  	/// @name Standard Constructors
+  	/// @{
+
 		SharedDiagonal() {
 		}
 		SharedDiagonal(const noiseModel::Diagonal::shared_ptr& p) :
@@ -45,6 +51,10 @@ namespace gtsam { // note, deliberately not in noiseModel namespace
 			noiseModel::Diagonal::shared_ptr(noiseModel::Diagonal::Sigmas(sigmas)) {
 		}
 
+    /// @}
+    /// @name Print
+    /// @{
+
 		/// Print
 		inline void print(const std::string &s) const { (*this)->print(s); }
 
diff --git a/gtsam/linear/SharedNoiseModel.h b/gtsam/linear/SharedNoiseModel.h
index 1d66e3495..bc90fee49 100644
--- a/gtsam/linear/SharedNoiseModel.h
+++ b/gtsam/linear/SharedNoiseModel.h
@@ -15,10 +15,16 @@
 
 namespace gtsam { // note, deliberately not in noiseModel namespace
 
+	/**
+	 * Just a convenient class to generate shared pointers to a noise model
+	 */
   struct SharedNoiseModel: public noiseModel::Base::shared_ptr {
 
     typedef noiseModel::Base::shared_ptr Base;
 
+  	/// @name Standard Constructors
+  	/// @{
+
     SharedNoiseModel() {}
     SharedNoiseModel(const noiseModel::Robust::shared_ptr& p): Base(p) {}
     SharedNoiseModel(const noiseModel::Gaussian::shared_ptr& p): Base(p) {}
@@ -27,6 +33,10 @@ namespace gtsam { // note, deliberately not in noiseModel namespace
     SharedNoiseModel(const noiseModel::Isotropic::shared_ptr& p): Base(p) {}
     SharedNoiseModel(const noiseModel::Unit::shared_ptr& p): Base(p) {}
 
+    /// @}
+    /// @name Dangerous constructors
+    /// @{
+
     #ifdef GTSAM_MAGIC_GAUSSIAN
     SharedNoiseModel(const Matrix& covariance) :
       Base(boost::static_pointer_cast<noiseModel::Base>(
@@ -45,30 +55,16 @@ namespace gtsam { // note, deliberately not in noiseModel namespace
              noiseModel::Isotropic::Sigma(GTSAM_DANGEROUS_GAUSSIAN, s))) {}
     #endif
 
+    /// @}
+    /// @name Print
+    /// @{
+
 		/// Print
 		inline void print(const std::string &s) const { (*this)->print(s); }
 
-    // Static syntactic sugar functions to create noisemodels directly
-    // These should only be used with the Matlab interface
-  	static inline SharedNoiseModel Sigmas(const Vector& sigmas, bool smart=false) {
-  		return noiseModel::Diagonal::Sigmas(sigmas, smart);
-  	}
-
-  	static inline SharedNoiseModel Sigma(size_t dim, double sigma) {
-  		return noiseModel::Isotropic::Sigma(dim, sigma);
-  	}
-
-  	static inline SharedNoiseModel Precisions(const Vector& precisions) {
-  	  return noiseModel::Diagonal::Precisions(precisions);
-  	}
-
-  	static inline SharedNoiseModel Precision(size_t dim, double precision) {
-  	  return noiseModel::Isotropic::Precision(dim, precision);
-  	}
-
-  	static inline SharedNoiseModel Unit(size_t dim) {
-  	  return noiseModel::Unit::Create(dim);
-  	}
+    /// @}
+    /// @name Static syntactic sugar (should only be used with the MATLAB interface)
+    /// @{
 
   	static inline SharedNoiseModel SqrtInformation(const Matrix& R) {
   	  return noiseModel::Gaussian::SqrtInformation(R);
@@ -78,6 +74,38 @@ namespace gtsam { // note, deliberately not in noiseModel namespace
   		return noiseModel::Gaussian::Covariance(covariance, smart);
   	}
 
+  	static inline SharedNoiseModel Sigmas(const Vector& sigmas, bool smart=false) {
+  		return noiseModel::Diagonal::Sigmas(sigmas, smart);
+  	}
+
+  	static inline SharedNoiseModel Variances(const Vector& variances, bool smart=false) {
+  		return noiseModel::Diagonal::Variances(variances, smart);
+  	}
+
+  	static inline SharedNoiseModel Precisions(const Vector& precisions, bool smart=false) {
+  	  return noiseModel::Diagonal::Precisions(precisions, smart);
+  	}
+
+  	static inline SharedNoiseModel Sigma(size_t dim, double sigma, bool smart=false) {
+  		return noiseModel::Isotropic::Sigma(dim, sigma, smart);
+  	}
+
+  	static inline SharedNoiseModel Variance(size_t dim, double variance, bool smart=false) {
+  		return noiseModel::Isotropic::Variance(dim, variance, smart);
+  	}
+
+  	static inline SharedNoiseModel Precision(size_t dim, double precision, bool smart=false) {
+  	  return noiseModel::Isotropic::Precision(dim, precision, smart);
+  	}
+
+  	static inline SharedNoiseModel Unit(size_t dim) {
+  	  return noiseModel::Unit::Create(dim);
+  	}
+
+    /// @}
+  	/// @name Serialization
+  	/// @{
+
     /** Serialization function */
     friend class boost::serialization::access;
     template<class ARCHIVE>
@@ -85,5 +113,8 @@ namespace gtsam { // note, deliberately not in noiseModel namespace
       ar & boost::serialization::make_nvp("SharedNoiseModel",
              boost::serialization::base_object<Base>(*this));
     }
+
+    /// @}
+
   };
 }