[Doc] Add documentation of Frame struct

src/python/frame.hpp

@@ -49,7 +49,7 @@ namespace se3
       void visit(PyClass& cl) const 
       {
         cl
-          .def(bp::init<const std::string&,Index, const SE3_fx&> ((bp::arg("name"),bp::arg("parent id"), bp::arg("placement")),
+          .def(bp::init<const std::string&,const Index, const SE3_fx&> ((bp::arg("name (string)"),bp::arg("parent_id (index)"), bp::arg("SE3 placement")),
                 "Initialize from name, parent id and placement wrt parent joint."))
 
           .add_property("name", &FramePythonVisitor::getName, &FramePythonVisitor::setName)
@@ -69,7 +69,7 @@ namespace se3
       static void expose()
       {
         bp::class_<Frame>("Frame",
-                           "ExtraFrames.\n\n",
+                           "A Plucker coordinate frame related to a parent joint inside a kinematic tree.\n\n",
 	                         bp::no_init
                          )
 	                       .def(FramePythonVisitor())

src/spatial/frame.hpp

@@ -27,32 +27,52 @@
 
 namespace se3
 {
-struct Frame
-{
-  typedef std::size_t Index;
-  
-  Frame() : name(random(8)), parent_id(), frame_placement()
+  ///
+  /// \brief What is a frame? TODO: complete this description.
+  ///
+  struct Frame
   {
+    typedef std::size_t Index;
+    
+    Frame() : name(random(8)), parent_id(), framePlacement() {} // needed by EIGEN_DEFINE_STL_VECTOR_SPECIALIZATION
+    
+    ///
+    /// \brief Default constructor of a Frame
+    ///
+    /// \param[in] name Name of the frame.
+    /// \param[in] parent_id Index of the parent joint in the kinematic tree.
+    /// \param[in] frame_placement Placement of the frame wrt the parent joint frame.
+    ///
+    Frame(const std::string & name, const Index parent_id, const SE3 & frame_placement):
+    name(name)
+    , parent_id(parent_id)
+    , framePlacement(frame_placement)
+    {}
+    
+    ///
+    /// \brief Compare the current Frame with another frame. Return true if all properties match.
+    ///
+    /// \param[in] other The frame to which the current frame is compared.
+    ///
+    bool operator == (const Frame & other) const
+    {
+      return name == other.name && parent_id == other.parent_id
+      && framePlacement == other.framePlacement ;
+    }
+    
+    /// \brief Name of the frame.
+    std::string name;
+    
+    /// \brief Index of the parent joint.
+    Index parent_id;
+    
+    /// \brief Placement of the frame wrt the parent joint.
+    SE3 framePlacement;
+    
+  }; // struct Frame
 
-  }
-
-  Frame(const std::string & name, Index parent, const SE3 & placement): name(name)
-                                                                      , parent_id(parent)
-                                                                      , frame_placement(placement)
-  {
-  }
-
-  bool operator == (const Frame & other) const
-  {
-    return name == other.name && parent_id == other.parent_id
-            && frame_placement == other.frame_placement ;
-  }
+} // namespace se3
 
-  std::string name;
-  Index parent_id;
-  SE3 frame_placement;
-};
 EIGEN_DEFINE_STL_VECTOR_SPECIALIZATION(se3::Frame)
 
-}
 #endif // ifndef __se3_frame_hpp__