Add pointer constructor for dynamic case

gtsam/base/OptionalJacobian.h

@@ -176,10 +176,11 @@ public:
     pointer_(NULL) {
   }
 
-  /// Constructor that will resize a dynamic matrix (unless already correct)
+  /// Construct from pointer to dynamic matrix
-  OptionalJacobian(Eigen::MatrixXd& dynamic) :
+  OptionalJacobian(Jacobian* pointer) : pointer_(pointer) {}
-      pointer_(&dynamic) {
+
-  }
+  /// Construct from refrence to dynamic matrix
+  OptionalJacobian(Jacobian& dynamic) : pointer_(&dynamic) {}
 
 #ifndef OPTIONALJACOBIAN_NOBOOST