add doxygen documentation

[[Imported from SVN: r5586]]

dune/solvers/iterationsteps/blockgsstep.hh

@@ -5,6 +5,13 @@
 
 #include "lineariterationstep.hh"
 
+/** \brief A linear Gauß-Seidel iteration step for convex problems which have a block-structure.
+ * 
+ *  \tparam OperatorType The linear operator type
+ *  \tparam DiscFuncType The block vector type of the right hand side and the iterates
+ *  \tparam BitVectorType The type of the bit-vector specifying degrees of freedom that shall be ignored.
+ *
+ */
 template<class OperatorType, 
          class DiscFuncType,
          class BitVectorType = Dune::BitSetVector<DiscFuncType::block_type::dimension> >
@@ -27,9 +34,15 @@ template<class OperatorType,
 
         //! Perform one iteration
         virtual void iterate();
-
+    
+        //! Return the solution
         virtual DiscFuncType getSol();
 
+        /** \brief Compute the residual of the current iterate of a (block) degree of freedom
+         *
+         *  \param index Global index of the (block) degree of freedom 
+         *  \param r Write residual in this vector
+         */
         virtual void residual(int index, VectorBlock& r) const;
 
     };