}

       }

     }

     }

   }

   }

   /// \brief Schnyder's planar drawing algorithms

   /// \brief Schnyder's planar drawing algorithms

   ///

   ///

   /// The planar drawing algorithm calculates location for each node

   /// The planar drawing algorithm calculates location for each node

   /// in the plane, which coordinates satisfies that if each edge is

   /// in the plane, which coordinates satisfies that if each edge is

   /// represented with a straight line then the edges will not

   /// represented with a straight line then the edges will not